The price of a dress was first discounted by a certain

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AAPL: Moderator; Posts: 2599; Joined: Sun Oct 29, 2017 2:08 pm; Followed by:2 members

The price of a dress was first discounted by a certain

by AAPL » Fri Sep 06, 2019 1:25 am

Veritas Prep

The price of a dress was first discounted by a certain percent and later by 25 percent of the discounted price. If these two discounts are equivalent to a single discount of 40 percent of the original price, what was the first discount?

A. 10%
B. 15%
C. 20%
D. 30%
E. 65%

OA C

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Source: Beat The GMAT — Problem Solving | Fri Sep 06, 2019 1:25 am

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Answer

by [email protected] » Fri Sep 06, 2019 4:44 pm

Hi AAPL,

We're told that the price of a dress was first discounted by a certain percent and again later by 25 percent of the discounted price - and that these two discounts are equivalent to a single discount of 40 percent of the original price. We're asked for the first discount. This question can be solved in a couple of different ways, including with a mix of TESTing THE ANSWERS and TESTing VALUES.

To start, since we're taking a discount OF an already discounted price, the 'base value' of the dress will be smaller for the second calculation. IF the sum of the two individual discounts was 40%, then the value of the discount would actually be LESS than that. This means that the sum of the two discounts (X + 25) will be GREATER than 40... but not much greater.

Let's TEST Answer C: 20%

IF....
The original price = $100...
a 40% discount would give us a price of $100 - (.4)($100) = $100 - $40 = $60
and
a 20% discount would give us a price of $100 - (.2)($100) = $100 - $20 = $80
followed by a 25% discount would give us... $80 - (.25)($80) = $80 - $20 = $60
The two end prices match, so this MUST be the answer.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich

Contact Rich at [email protected]

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by Scott@TargetTestPrep » Mon Sep 09, 2019 6:27 pm

AAPL wrote:Veritas Prep

The price of a dress was first discounted by a certain percent and later by 25 percent of the discounted price. If these two discounts are equivalent to a single discount of 40 percent of the original price, what was the first discount?

A. 10%
B. 15%
C. 20%
D. 30%
E. 65%

OA C

We can let the original price be 100 and the first discount be n. We create the equation:

100 x (100 - n)/100 x 75/100 = 100 x 60/100

(100 - n) x 3/4 = 60

100 - n = 80

n = 20

Answer: C

Scott Woodbury-Stewart
Founder and CEO
[email protected]