Percent change problem

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Sat Feb 23, 2008 9:36 am

Percent change problem

by mmirand80 » Sun Apr 06, 2008 6:29 pm
Can someone help me with the following problem:

A file cabinet that originally cost $52 is on sale at 15% off. If the sales tax on office furniture is 5% of the purchase price, how much would it cost to buy the file cabinet at its sale price?

The detailed the explanation, the better. Thanks!
Source: — Problem Solving |

User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Sun Apr 06, 2008 8:58 pm
Let's do this in two steps:

(1) calculate sale price:

15% off of $52. So, the sale price is 85% of the original price, or .85(52).

Now, we could actually calculate it the traditional way, or we could just kind of "figure it out".

10% of $52 is 5.20. Half of that would be 5%, so another 5% is 2.60. So, 15% off is 5.20 + 2.60 = 7.80.

52.00 - 7.80 = 44.20.

(2) calculate the tax:

5% tax, so we owe an extra 5% of 44.20. 10% of 44.20 woudl be 4.42, so 5% is half of that, which is 2.21.

(3) find the final cost, including tax:

44.20 + 2.21 = 46.41.

* * *

If I actually saw the answer choices, I may have decided to backsolve/reason it out instead - it would largely depend on how spread out they are.
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course

Senior | Next Rank: 100 Posts
Posts: 59
Joined: Sat Mar 08, 2008 5:15 pm
Location: Cincinnati
Thanked: 3 times

by ritz » Mon Apr 07, 2008 5:20 pm
anoher way to do it is..
price given 52
there are 2 factors which are affecting the price, sale tax & the discount.
both the percentages are given, so simply apply them together..

85*105*52/100*100
simplyfi it & thats your answer..

Whenever the tax, discount & all those parameters which affect the price of items are given, apply them together. This will ease out your calculations.
regards
Ritz