GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 17 Oct 2019, 21:19

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58408
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10  [#permalink]

Show Tags

22 Mar 2018, 23:56
00:00

Difficulty:

25% (medium)

Question Stats:

92% (01:10) correct 8% (01:31) wrong based on 38 sessions

HideShow timer Statistics

Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10^2 grams of sugar. The number of grams of sugar in solution Y is how many times the number of grams of sugar in solution X?

(A) 0.0002
(B) 0.002
(C) 200
(D) 2,000
(E) 20,000

_________________
Current Student
Joined: 07 Jan 2016
Posts: 1088
Location: India
GMAT 1: 710 Q49 V36
Re: Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10  [#permalink]

Show Tags

23 Mar 2018, 00:19
Bunuel wrote:
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10^2 grams of sugar. The number of grams of sugar in solution Y is how many times the number of grams of sugar in solution X?

(A) 0.0002
(B) 0.002
(C) 200
(D) 2,000
(E) 20,000

8x10^2/4x10^ -2

= 2 x 10^2 / 10^-2 = 2 x 10^4

(E) imo
Senior SC Moderator
Joined: 22 May 2016
Posts: 3548
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10  [#permalink]

Show Tags

23 Mar 2018, 08:53
Bunuel wrote:
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10^2 grams of sugar. The number of grams of sugar in solution Y is how many times the number of grams of sugar in solution X?

(A) 0.0002
(B) 0.002
(C) 200
(D) 2,000
(E) 20,000

Y, number of grams of sugar = $$8*10^2$$
X, number of grams of sugar = $$4*10^{-2}$$

Number of grams of sugar in Y is how many times the number of grams of sugar in X?

$$\frac{Y}{X}=\frac{8*10^2}{4*10^{-2}}=$$?

1) Move $$10^{-2}$$ to the numerator.
Any number with a negative power in the denominator can be moved to the numerator.
Change the exponent's sign
$$\frac{Y}{X}=\frac{8*10^2}{4*10^{-2}}=\frac{8*10^2*10^2}{4}=$$

$$\frac{8*10^{(2+2)}}{4}=\frac{8*10^4}{4}=2*10^{4}=20,000$$

OR
2) Division of exponents (same base) =
Keep the base, subtract the exponents

$$\frac{Y}{X}=\frac{8*10^2}{4*10^{-2}}=\frac{8*10^{2-(-2)}}{4}=$$

$$\frac{8*10^{2+2}}{4}=\frac{8*10^4}{4}=2*10^4=20,000$$

OR
3) divide integers, then powers of 10.
Integers and powers of 10 are factors of the numbers. Results of separate operations are also factors -- i.e., multiply the results

Number in Y is how many times number in X?
Number in Y = $$8*10^2$$
Number in X = $$4*10^{-2}$$

$$\frac{8}{4} = 2$$
$$\frac{10^2}{10^{-2}}=10^{2-(-2)}=10^{2+2}=10^4$$
Multiply results: $$2*10^4=20,000$$

_________________
SC Butler has resumed! Get two SC questions to practice, whose links you can find by date, here.

Choose life.
Manager
Joined: 28 Jan 2018
Posts: 50
Location: Netherlands
Concentration: Finance
GMAT 1: 710 Q50 V36
GPA: 3
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10  [#permalink]

Show Tags

23 Mar 2018, 09:43
Bunuel wrote:
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10^2 grams of sugar. The number of grams of sugar in solution Y is how many times the number of grams of sugar in solution X?

(A) 0.0002
(B) 0.002
(C) 200
(D) 2,000
(E) 20,000

Number of grams of sugar in solution Y:X $$= \frac{8*10^{2}}{4*10^{-2}} = \frac{8*10^{2}*10^{2}}{4} = 2*10^{4} = 20,000 (E)$$

Key point to remember: $$a^{-b} = \frac{1}{a^{b}}$$ in this case: $$4*10^{-2} = \frac{4}{10^2}$$
Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2816
Re: Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10  [#permalink]

Show Tags

26 Mar 2018, 17:46
Bunuel wrote:
Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10^2 grams of sugar. The number of grams of sugar in solution Y is how many times the number of grams of sugar in solution X?

(A) 0.0002
(B) 0.002
(C) 200
(D) 2,000
(E) 20,000

(8 x 10^2)/(4 x 10^(-2))

(8/4) x 10^(2 - (-2))

2 x 10^4

20,000

_________________

Jeffrey Miller

Jeff@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Re: Solution X contains 4*10^(–2) grams of sugar. Solution Y contains 8*10   [#permalink] 26 Mar 2018, 17:46
Display posts from previous: Sort by