Quant Question of the Day Chat

If x^2 + 10y^2 - 6xy- 2y + 1 = 0, what is the value of x?

You can write this as( x^2-6xy+9y^2)+y^2-2y+1= 0

Solve for x we get -3/3

Ans- 3

So on simplifying you get: (x-3y)² + (y-1)² = 0, right? How do you get x=3 from this?

Here to get the sum as 0. x should be equal 3y and y=1. So x=3y is x=3(1)=3

In the xy-plane, region Q consists of all points (x,y) such that x^2+y^2≤100. Is the point (a,b)in region Q?
(1) a+b=14

(2) a>b

I think Together not sufficient.

What is the remainder when 2^99 is divided by 99?

A. 17
B. 15
C. 13
D. 11
E. 9

Try this solution. Easy to understand and very simplified
what-is-the-remainder-when-2-99-is-divided-by-309576.html#p2430551

Baltimore native Michael Phelps needs a display to store his 23 gold, 3 silver, and 2 bronze medals. He is planning to display them in 4 rows of 7 medals each. How many ways can the medals be arranged so that in each row the sequence of medal color (or metal type) is the same in both directions? (Assume medals of the same color/type are indistinguishable. The order of the rows makes a difference.)

A. 48

B. 320

C. 640

D. 720

E. 768

K, L, M, and N are positive integers. If K is divided by L then we get a quotient M and a remainder N. When the value obtained after the division is expressed in decimal form, the value is 80.025, Which of the following must be true?

A. k = 80l + 0.25l

B. k = 80l + 0.025n

C. k = 3200l + 0.25n

D. k = 3200n

E. k = 3201n

I got 108 and counting after 3-4 mins. I think, it will be in our best interest to skip this question, unless we are missing some concept that can solve this within 3 mins

The average of 5 quantities is 6. The average of 3 of them is 8. What is the average of the remaining two numbers

please explain this someone

ok i got it thanks

u break the decimal in fraction and do adjustments... will reach the result

i think its c , as 8,6 is one pair.... using both statements

A school administrator will assign each student in a group offstudents to one of m classrooms. If 3 ‹ m < 13 < n, is it possible to assign each of the n students to one of the m classrooms so that each classroom has the same number of students assigned to it?
1. It is possible to assign each of 3n students to one of m classrooms so that gach classroom has the same number of students assigned to it.
2. It is possible to assign each of 13n students to one of m classrooms so that each classroom has the same number of students assigned to it.

Please help me out

nswer is b i think

answer*

we have to prove n is divided by m and it leaves no remainder

if n is divided by m completely then only each of the n student will be able to be divided equally in m classes

in statement 2 13n is completely divisible by m and since m is less than 13 and 13 is a prime number ....in order to make 13n divisible by m , n must be divisible by m

Thanks for explanation

DS Question 1 - June 10

Two positive integers a and b are divisible by 5, which is their largest common factor. What is the value of a and b?

(1) The lowest number that has both integers a and b as its factors is the product of one of the integers and the greatest common divisor of the two integers.

(2) The smaller integer is divisible by 4 numbers and has the smallest odd prime number as its factor.

Source: eGMAT | Difficulty: Hard

PS Question 1 - June 10

A closed cylindrical tank contains 36π cubic feet of water and is filled to half its capacity. When the tank is placed upright on its circular base on level ground, the height of the water in the tank is 4 feet. When the tank is placed on its side on level ground, what is the height, in feet, of the surface of the water above the ground?

(A) 2
(B) 3
(C) 4
(D) 6
(E) 9

Source: Official Guide | Difficulty: Medium
_________________

I think the correct answer is not listed. The volume of a cylinder = pi*r^2*h. We know the tank has a capacity of 36 pi cubic feet, so pi*r^2*h = 36 pi. This means that r^2*h/2 = 18 and we are given that h/2 = 4 feet. 18 is 3*3*2, and we need to divide by h/2 or 4, to get r^2= 3*3*1/2. r = sqrt 9/2. When the half-full tank is placed on its side on level ground, the water will come up to r.
If the half capacity were 36 pi instead of 18 pi with height 4ft, that would give us r=3, but I believe this question is incorrect with the answers provided. Can anyone help correct my reasoning?