\(\dfrac{7}{\frac15}+\dfrac{5}{\frac17}=\)

Jay@ManhattanReview: GMAT Instructor; Posts: 3008; Joined: Mon Aug 22, 2016 6:19 am; Location: Grand Central / New York; Thanked: 470 times; Followed by:34 members

Re: \(\dfrac{7}{\frac15}+\dfrac{5}{\frac17}=\)

by Jay@ManhattanReview » Wed Jun 03, 2020 1:28 am

Vincen wrote: ↑
Tue Jun 02, 2020 7:40 am
\(\dfrac{7}{\frac15}+\dfrac{5}{\frac17}=\)

A. 35/74

B. 74/35

C. 35

D. 70

E. 74

[spoiler]OA=D[/spoiler]

Source: Official Guide

\(\dfrac{7}{\frac15}+\dfrac{5}{\frac17}=\dfrac{7*5}{1} + \dfrac{5*7}{1}=35+35=70\)

The correct answer: D

Hope this helps!

-Jay
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GMAT/MBA Expert

Scott@TargetTestPrep: GMAT Instructor; Posts: 8086; Joined: Sat Apr 25, 2015 10:56 am; Location: Los Angeles, CA; Thanked: 43 times; Followed by:29 members

Re: \(\dfrac{7}{\frac15}+\dfrac{5}{\frac17}=\)

by Scott@TargetTestPrep » Sat Jun 06, 2020 5:45 am

Vincen wrote: ↑
Tue Jun 02, 2020 7:40 am
\(\dfrac{7}{\frac15}+\dfrac{5}{\frac17}=\)

A. 35/74

B. 74/35

C. 35

D. 70

E. 74

[spoiler]OA=D[/spoiler]

Source: Official Guide

Solution:

Let’s treat each fraction separately. If we multiply the first fraction by 5/5, we get 5 x 7 / 1 = 35. If we multiply the second fraction by 7/7, we get 7 x 5 / 1 = 35.

Thus, the sum is 35 + 35 = 70.

Answer: D

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