Problem Solving

BTGModeratorVI wrote: ↑

Sun Sep 27, 2020 7:05 am

In the first quarter of 2008, Harry's Hardware Store sold 300 hammers and 12,000 nails. In the second quarter of 2008, the store sold 375 hammers and 18,000 nails. By approximately what percent did the ratio of hammers sold to nails sold decrease from the first quarter to the second quarter.

A. 0.4%
B. 2.1%
C. 2.5%
D. 17%
E. 25%

Answer: D
Source: Manhattan prep

1st quarter: hammers/nails = 300/12,000 = 150/6000
2nd quarter: hammers/nails = 375/18,000 = 125/6000
ASIDE: It's useful to write both ratios with the same denominator. This allows us to IGNORE the denominator and focus solely on the numerators.

So, our ratio went from 150/6000 to 125/6000
Ignoring the denominators, we went from 150 to 125
The percent change = 100(difference in values)/(original value)
= (100)(150 - 125)/150
= (100)(25)/150)
= (100)(1)/(6)
= 100/6
≈ 16.666...

Answer: D