A drought decreased the amount of water in city X’s reservoirs from 11

Question

A drought decreased the amount of water in city X’s reservoirs from 118 million gallons to 96 million gallons. If the reservoirs were at 79 percent of total capacity before the drought began, approximately how many million gallons were the reservoirs below total capacity after the drought?

A. 67
B. 58
C. 54
D. 46
E. 32

A. 67
B. 58
C. 54
D. 46
E. 32

Divyadisha · Answer

IMO 'C' is the answer

vivekgautam1 · Answer

Let capacity be 'c'
118 = 79% of c
i.e.
118 =  \frac{79}{100}  * c

or by ballparking,
120 =  \frac{80}{100}  * c

So, c =150

So, after the draught, the reservoir is 150 - 96 million gallons below the capacity, i.e. 54 million gallons.
So,   54

peachfuzz · Answer

79/100(x)= 118
x~150

150-96=54

C. 54

msk0657 · Answer

This is how I tried...

Before drought reservoir has 118 MG and after drought 96 MG.

Now the question mentioned that 79 percent of total capacity before the drought.

let T be the total capacity of the reservoir.

Now we can equate before cases i.e 79/100(T) = 118.
Lets take approximate values for easy calculation 80/100(T) = 120 => T = 150 MG.

We need to subtract total - after drought case = 150 - 96 = 54 MG..

Option C is correct answer...

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.

A drought decreased the amount of water in city X’s reservoirs from 11

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

GMAT Problem Solving (PS) Questions

A drought decreased the amount of water in city X’s reservoirs from 11

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