pradeepkaushal9518 wrote:A retailer bought a shirt at wholesale and marked it up 80% to its initial retail price of $45. By how many more dollars does he need to increase the price to achieve a 100% markup?

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One approach would be to plug in the answer choices, which represent the increase needed from 45 to achieve a 100% markup.

Let w = wholesale price.

C)
100% markup = 45+3 = 48.
w = 48/2 = 24. (Since a 100% markup is the wholesale price doubled.)
Now let's see whether w=24 gives us an initial markup of $45:
80% of 24 = .8*24 = 19.2.
Initial mark-up = 24 + 19.2 = 43.2.
Too small. Need a bigger answer.

D)
100% markup = 45+4 = 49.
w = 49/2 = 24.5
Incorrect. The wholesale price must be an integer since the initial markup = 45.

The correct answer is E.

Here's the algebraic solution:

A retailer marked it up 80% to...45:
1.8w = 45
w = 45/1.8 = 450/18 = 25

100% markup of the wholesale price:
2w = 2*25 = 50. (A 100% mark-up means the wholesale price doubled.)

100% markup - initial markup = 50-45 = 5.

The correct answer is E.

GMATGuruNY wrote:

pradeepkaushal9518 wrote:A retailer bought a shirt at wholesale and marked it up 80% to its initial retail price of $45. By how many more dollars does he need to increase the price to achieve a 100% markup?

1
2
3
4
5

One approach would be to plug in the answer choices, which represent the increase needed from 45 to achieve a 100% markup.

Let w = wholesale price.

C)
100% markup = 45+3 = 48.
w = 48/2 = 24. (Since a 100% markup is the wholesale price doubled.)
Now let's see whether w=24 gives us an initial markup of $45:
80% of 24 = .8*24 = 19.2.
Initial mark-up = 24 + 19.2 = 43.2.
Too small. Need a bigger answer.

D)
100% markup = 45+4 = 49.
w = 49/2 = 24.5
Incorrect. The wholesale price must be an integer since the initial markup = 45.

The correct answer is E.

Here's the algebraic solution:

A retailer marked it up 80% to...45:
1.8w = 45
w = 45/1.8 = 450/18 = 25

100% markup of the wholesale price:
2w = 2*25 = 50. (A 100% mark-up means the wholesale price doubled.)

100% markup - initial markup = 50-45 = 5.

The correct answer is E.

Dear GMATGuru,

Isnt the algebraic solution much faster in this case?
What you recommend?