In August, Mr. Zelenskys earnings were 40% of the total earnings

Question

In August, Mr. Zelensky’s earnings were 40% of the total earnings of the Zelensky household. In September, Mr. Zelensky earned 20% less than he did in August. If the rest of the family’s income remained the same in August and September, Mr. Zelensky’s earnings were closest to what percentage of the total Zelensky family income in September?

(A) 20
(B) 28
(C) 32
(D) 35
(E) 40

(A) 20 
(B) 28 
(C) 32 
(D) 35 
(E) 40

rajatchopra1994 · Answer

Explanation:

Let the total earnings of family is 100 for August

Zelensky earning for August will be 40%. i.e. 40
Rest of family income will be = 100 - 40 = 60
For September, it will be 40x0.8 = 32

% = 32 * 100 /(60+32)
= 34.7 %

IMO-D

Posted from my mobile device

saijyoti · Answer

GMATNinja

Hi GmatNinja,

Can you please explain how did we arrive to 0.8 in the statement (0.4*0.8) mentioned in your video. I think its 1-0.2 but when do we apply this, only in case of decrease? Can you also give a similar example for percent increase as well?

Thanks in advance!!!

GMATNinja · Answer

Yes, that's correct, saijyoti -- if something decreases by 20%, you can just multiply it by 0.8 to calculate the new value. If something increases by 20%, the idea is the same: you can just multiply by 1.2. For example, imagine that a certain item's original price was $60, and then the price increases by 20%. You could calculate 20% of $60, and add that result to $60. Or you could just multiply by 1.2. If you're not sure, try it both ways, and see what happens.

For much more on percents, check out this video .

Jarvis07 · Answer

Let's assume the total earnings of the Zelensky household in August to be 100. Therefore, Mr. Zelensky earned 40 out of the 100 in August.

In September, Mr. Zelensky earned 20% less than what he earned in August, which means he earned 0.8 times his August earnings. Therefore, his September earnings are:

0.8 * 40 = 32

The rest of the family's income remained the same, so the total income of the Zelensky family in September is:

32 + 60 = 92

Now, we can find the percentage of Mr. Zelensky's earnings to the total Zelensky family income in September:

(32/92) * 100 = 34.78 , which is closest to  35 .

Therefore, the answer is (D) 35.

Prince1890Sharma · Answer

Hello All,

Can anyone tell how to solve 32/92 easily, I took an approximation for 30/90..It comes out to be 33.33%, but how to surely select between 32 and 35? any advice?  GMATNinja

GMATNinja · Answer

You could first reduce 32/92 to 8/23.

You know that 8/23 is a little bit larger than 8/24. And since 8/24 = 1/3 (or 33 1/3%), 8/23 must be a little bit larger than 1/3 (33 1/3%).

So even though 32% and 35% are both close to 33 1/3%, you have to go with the one that's greater than 33 1/3%.

I hope that helps a bit!

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

In August, Mr. Zelenskys earnings were 40% of the total earnings

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions

In August, Mr. Zelenskys earnings were 40% of the total earnings

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards