GMAT Math Questions | Percentage Q8

GMAT Sample Questions | Percentages & Fractions

The given question is a GMAT 500 level problem solving question from the topic Percentages. The concept tested in this GMAT sample question is finding out % increase and % decrease from a base value.

Question 8: The difference between the value of a number increased by 12.5% and the value of the original number decreased by 25% is 30. What is the original number?

  1. 60
  2. 80
  3. 40
  4. 120
  5. 160

Get to Q51 in GMAT Quant

Online GMAT Course
@ INR 3500

Video Explanation

GMAT Live Online Classes

Starts Tue, Sep 14, 2021

Explanatory Answer | GMAT Percentage Q8

Step 1 of solving this GMAT Percentage Question: Deduce the given data from the question stem

These are classic word problems. What is tested is one’s ability to translate what is given in words into mathematical equations and expressions. Invest adequate time to understand what is stated and write correct equations. Usually, solving these equations will not be an issue.

Let the original number be x.
Let A be the value obtained when x is increased by 12.5%.
Therefore, A = x + 12.5% of x
Let B be the value obtained when x is decreased by 25%.
Therefore, B = x − 25% of x

Step 2 of solving this GMAT Percentage Question: Compute the value of the original number

The difference between the value of x increased by 12.5% (i.e., A) and the value of x decreased by 25% (i.e., B) is 30.
i.e., A − B = 30
i.e., x + 12.5% of x − (x − 25% of x) = 30
x + 12.5% of x − x + 25% of x = 30
37.5% of x = 30

x = \\frac{30}{37.5}) × 100 = 80
The original number is 80

Choice B is the correct answer.

GMAT Online Course
Try it free!

Register in 2 easy steps and
Start learning in 5 minutes!

★ Sign up

Already have an Account?

★ Login

GMAT Live Online Classes

Next Batch Sep 14, 2021

★ GMAT Live Info

GMAT Coaching in Chennai

Next Batch
after Lockdown

★ GMAT Class Info

GMAT Coaching in Chennai

Sign up for a Free Demo of our GMAT Classes in Chennai

★ Schedule Demo

GMAT Ratios Percent Fractions Videos On YouTube

Additional Practice Questions in Ratio Proportion, Mixtures, Percents, Fractions, Profits, and Interest

GMAT Sample Questions | Topicwise GMAT Questions

Where is Wizako located?

Wizako - GMAT, GRE, SAT Prep
An Ascent Education Initiative
14B/1 Dr Thirumurthy Nagar 1st Street
Chennai 600 034. India

How to reach Wizako?

Phone: (91) 44 4500 8484
Mobile: (91) 95000 48484
WhatsApp: WhatsApp Now
Leave A Message

404 Not Found

404 Not Found