Author 
Message 
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
17 Sep 2017, 18:46
[GMAT math practice question] If 3 persons are selected at random from 8 persons for 3 positions present, vicepresent, and secretary, how many such ways are possible? A. 56 B. 70 C. 240 D. 336 E. 1680 => 8P 3 = 8 x 7 x 6 = 336 Ans: D
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
20 Sep 2017, 00:57
[GMAT math practice question] What is the range of 25 consecutive even numbers? A. 44 B. 46 C. 48 D. 50 E. 52 => 50 – 2 = 48 Ans: C
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
21 Sep 2017, 00:58
[GMAT math practice question] For a positive integer n, if 5^n is a factor of 25!, but 5^{n+1} is not a factor of 25!, what is the value of n? A. 5 B. 6 C. 7 D. 8 E. 9 => 25! = 1 x 2 x … x 5 x … x 10 x … x 15 x … x 20 x … x 25 = 1 x … x 4 x 6 x … x 9 x 11 x … x 14 x 16 x … x 19 x 21 x … x 24 x 5 x 10 x 15 x 20 x 25 = 1 x … x 4 x 6 x … x 9 x 11 x … x 14 x 16 x … x 19 x 21 x … x 24 x ( 5 x 5 x 2 x 5 x 3 x 5 x 4 x 5^2 ) = 1 x … x 4 x 6 x … x 9 x 11 x … x 14 x 16 x … x 19 x 21 x … x 24 x (2 x 3 x 4 x 5^6 ) Thus n = 6. Ans: B
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
24 Sep 2017, 19:24
[GMAT math practice question] What is the number of multiples of 4 between 25 and 26, inclusive? A. 8 B. 9 C. 10 D. 11 E. 12 => ( 2^6  2^5 ) / 4 + 1 = 32/4 + 1 = 8 + 1 = 9 Ans: A
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
24 Sep 2017, 19:25
[GMAT math practice question] There are 5 integers and x≤y≤r≤s≤t. If the median of them is 80 and the average (arithmetic mean) of them is 100, what is the smallest possible value of t? A. 110 B. 120 C. 130 D. 140 E. 150 => In order to have the smallest value of t, we need to maximize x, y and r. Then we have x = 80, y = 80 and r = 80. After that, in order to have the smallest value of t, we need to maximize s and so we have s = 130 and t = 130. Ans: C
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
27 Sep 2017, 01:40
[GMAT math practice question] The formula for the sum of squares of integer between 1 and n is n(n+1)(2n+1) / 6 = 1^2 + 2^2 + … + n^2. The is the value of 11^2 + 12^2 + … + 20^2? A. 2470 B. 2475 C. 2480 D. 2485 E. 2490 => 11^2 + 12^2 + … + 20^2 = ( 1^2 + 2^2 + … + 20^2 ) – (1^2 + 2^2 + … + 10^2) = 20∙21∙41/6  10∙11∙21/6 = 2870 – 385 = 2485 Ans: D
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
28 Sep 2017, 02:31
[GMAT math practice question] If x+(1/x)=4, what is the value of x^2+(1/x)^2? A. 12 B. 13 C. 14 D. 15 E. 16 => x^2+(1/x)^2 = ( x + 1/x )^2 – 2x(1/x) = 4^2 – 2 = 16  2 = 14 Ans: C
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
29 Sep 2017, 01:29
[GMAT math practice question] What is the area of the triangle with points (2,4), (3,6), (5,2)? A. 4 B. 5 C. 6 D. 7 E. 8 => The area of the triangle with points (a,b), (c,d) and (e,f) is 1/2a c b d e a f b = 1/2 adbc+cfde+ebaf  1/22 3 4 6 5 2 2 4 = 1/2 1212+630+204 = 1/2∙8=4 Ans: A
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
01 Oct 2017, 18:18
[GMAT math practice question] What is the product of all the roots on the equation (x2)2=x2? A. 2 B. 2 C. 3 D. 3 E. 6 => (x2)^2=x2 ⬄ x2^2=x2 ⬄ x2^2x2 = 0 ⬄ x2 ( x2  1 ) = 0 ⬄ x2 = 0 or x2 = 1 ⬄ x = 2 or x2 = ±1 ⬄ x = 2 or x = 2 ±1 ⬄ x = 2 or x = 3 or x = 1 1 * 2 * 3 = 6 Ans: E
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
01 Oct 2017, 18:21
[GMAT math practice question] If 3^x>10, which of the following must be true? I. x>2 II. x>3 III. x>4 A. I only B. II only C. III only D. I and II only E. I, II, and III => 3^x>10 > 9 = 3^2 Then, we have x > 2.abc… Thus x > 2. Therefore, A is the answer. Answer: A
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
04 Oct 2017, 01:44
[GMAT math practice question] If n is the product of 3 different prime numbers, how many factors does n have except 1 and n? A. 6 B. 7 C. 8 D. 9 E. 10 => n = p*q*r where p, q and r are different prime numbers. Then the number of factors of n is (1+1)(1+1)(1+1) = 8 including 1 and n, since the exponents of p, q and r are 1. Thus the number of factors of n except 1 and n is 8 – 2 = 6. Answer: A
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
05 Oct 2017, 03:17
[GMAT math practice question] n number of people are attending a meeting. All of them shake hands with each other. If all attendees shake hands 210 times, what is the value of n? A. 15 B. 19 C. 20 D. 21 E. 25 => nC 2 = n(n1)/2 = 210 n(n1) = 420 n(n1) – 420 = 0 n^2 – n – 420 = 0 (n21)(n+20) = 0 n = 21 or n = 21 n = 21 since n must be positive. Answer: D
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
06 Oct 2017, 02:43
[GMAT math practice question] Which of the following inequalities is equal to 2xx<6? A. 2<x<0 B. 0<x<6 C. 2<x<6 D. 2<x<2 E. 6<x<6 => We should split real number of x into two cases x ≥ 0 and x < 0. Case 1: x ≥ 0 2xx<6 ⬄  2x – x  < 6 ⬄ x < 6 ⬄ 6<x<6. From the assumption of the case, x ≥ 0, we have 0 ≤ x < 6. Case 2: x < 0 2xx<6 ⬄  2x + x  < 6 ⬄ 3x < 6 ⬄ x < 2 ⬄ 2<x<2. From the assumption of the case, x < 0, we have 2<x<0. Thus, we have 2 < x < 6. Answer: C
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
08 Oct 2017, 18:04
[GMAT math practice question] When  1  √2 + 1  √3 + √2 + √3  = ? A. 2 B. 1 C. 0 D. 1 E. 2 =>  1  √2 + 1  √3 + √2 + √3  = ( 1  √2 ) – ( 1  √3 ) + ( √2 + √3 ) = 1 + √2 – 1 + √3 + √2 + √3 = 2 Answer: A
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
08 Oct 2017, 18:06
[GMAT math practice question] If 8x=2y, what is the value of x, in terms of y? A. x=2^{3y2} B. x=4y C. x=4^{y2} D. x=2^{y3} E. x=2y => 8x = 2^y ⬄ 2^3x = 2^y ⬄ x = 2^{y3} Answer : D
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
18 Oct 2017, 03:20
[GMAT math practice question] Which of the following is closest to (1+2^18)/(2^4+2^10)? A. 2^5 B. 2^6 C. 2^7 D. 2^8 E. 2^9 => (1+2^18)/(2^4+2^10) = (1+2^18)/(2^4(1+2^6)) = (1+2^6)(12^6+2^12)/(2^4(1+2^6)) = (12^6+2^12)/2^4 ≒ 2^8 Therefore, the answer is D. Answer: D
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
19 Oct 2017, 00:03
[GMAT math practice question] If 0.010<x√5<0.011, approximation of 1/√51/x is which of the following options? A. 0.01 B. 0.002 C. 0.02 D. 0.003 E. 0.03 => 1/√51/x = x√5/x√5 From 0.010<x√5<0.011, we have 0.010 + √5<x <0.011 + √5. We have 1/0.010+ √5 < 1/x < 1/0.011+ √5 or 1/0.010√5+5 < 1/x√5 < 1/0.011√5+5. 0.010/0.010√5+5 < x√5/x√5 < 0.011/0.011√5+5. The approximation of x√5/x√5 is 0.01/5=0.002 Thus, the answer is B. Answer: B
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
20 Oct 2017, 01:12
If x5=√x+√5 , which of followings is true? A. x^2+12x+16 = 0 B. x^212x+16 = 0 C. x^2+6x+8 = 0 D. x^26x+8 = 0 E. x^2+6x8 = 0 => x5=√x+√5 is equivalent to (√x+√5)(√x√5)=√x+√5 or √x+√5=1 √x=√5 + 1 x = 5 + 2√5 + 1 = 6 + 2√5 (x6)^2 = 20 x^2 – 12x + 36 = 20 x^2 – 12x + 16 = 0 Therefore, the answer is B. Answer: B
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
22 Oct 2017, 21:21
[GMAT math practice question] (6^3)a+(6^2)b+6c+d=821, where a, b, c, and d are integers from 0 to 5, inclusively, c=? A. 0 B. 1 C. 2 D. 3 E. 4 => 821 = 6*136 + 5 136 = 6*22 + 4 22 = 6*3 +4 821 = 6*136 + 5 = 6*(6*22+4) + 5 = 6 * ( 6 * (6 *3 + 4) + 4 ) + 5 = 6 * ( 6^2*3 + 6*4 + 4 ) + 5 = 6^3*3 + 6^2*4 + 6*4 + 5 = 6^3*a + 6^2*b + 6*c + d Thus a = 3, b = 4, c = 4 and d = 5. Therefore, the answer is E. Answer: E
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6040
GPA: 3.82

Re: Math Revolution Approach (PS)
[#permalink]
Show Tags
22 Oct 2017, 21:23
[GMAT math practice question] Attachment:
1023.png [ 2.42 KiB  Viewed 213 times ]
In the above table, scores and numbers of people are shown. If the median score is not represented as the score shown on the table, which of the following scores can be the value of x? A. 2 B. 3 C. 4 D. 5 E. 6 => The sum of numbers for a+1 and a+2 is 15 = 7 + 8. If 2 + 8 + x = 15, we don’t have the median on the table. Thus, 10 + x = 15 and we have x = 5. Therefore, the answer is D. Answer : D
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare The oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $99 for 3 month Online Course" "Free Resources30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons  try it yourself"




Re: Math Revolution Approach (PS) &nbs
[#permalink]
22 Oct 2017, 21:23



Go to page
Previous
1 ... 13 14 15 16 17 18 19 ... 27
Next
[ 528 posts ]



