GMAT Quant : Ratio Proportion

Concept: Ratio Proportion

The GMAT Sample Math Practice question is a ratio proportion problem on dividing a sum of money among 3 people.

Question: Three friends Alice, Bond and Charlie divide $1105 amongst them in such a way that if $10, $20 and $15 are removed from the sums that Alice, Bond and Charlie received respectively, then the share of the sums that they got will be in the ratio of 11 : 18 : 24. How much did Charlie receive?

  1. $495
  2. $510
  3. $480
  4. $375
  5. $360

Explanatory Answer

Video explanation will be added soon.

Let the amount of money received by A, B and C be x, y and z respectively.
Sum of money with the three of them, x + y + z = 1105.
It is mentioned that the money that they possess are in the ratio 11:18:24, after removing $10, $20 and $15 respectively.
Then x - 10 : y - 20 : z -15 will be in the ratio 11 : 18 : 24

So, x – 10 = 11k, y – 20 = 18k and z – 15 = 24k
Adding the money left with the three of them after removing $10, $20 and $15 respectively, we get
x – 10 + y – 20 + z – 15 = 11k + 18k + 24k
Or x + y + z – 10 – 20 – 15 = 53k
Or x + y + z – 45 = 53k
We know x + y + z = 1105.
So, 1105 – 45 = 53k
1060 = 53k
or k = 20.

To compute the amount that C received, substitute value of k in ratio of z.

We know that z - 15 = 24k
z - 15 = 24 * 20 = 480

Therefore, z = 480 + 15 = $495
Charlie received 495$

The correct choice is (A) and the correct answer is $495.

Target Q-51 in GMAT Quant. Make it a reality @ INR 2500!

Most Comprehensive & Affordable GMAT Online Course for Quant. 20 topics.
Focused preparation for the hard-to-crack eggs in the GMAT basket!

Try it Free Now
gmat online classes

Next Weekend GMAT batch starts Nov 9, 2019. Call +91 96000 48484.

Sat 5 PM to 8 PM and Sun 9:30 AM to 12:30 PM at Velachery, Chennai for 12 weekends. Start Now