mangomangodolly wrote:On July 15, 1984, one United States dollar bought 252 Japanese yen. On July 15, 1995, one United States dollar bought 89 Japanese yen. At these rates, approximately how much more was the cost, in United States dollars, of 10,000 Japanese yen on July 15, 1995, than on July 15, 1984 ?

A. $160
B. $110
C. $70
D. $60
E. $40

We can solve this question using equivalent ratios. For each date, we'll use the ratio of $US/Yen

1984: 1/252 = x/10,000
Cross multiply to get: 252x = 10,000
So, x = 10,000/252
Approximate to get x = 10,000/250 = 40
So, in 1984, 10,000 yen was worth approximately $40 USD

1995: 1/89 = y/10,000
Cross multiply to get: 89y = 10,000
So, y = 10,000/89
Approximate to get y = 10,000/90 = 1000/9 = 111
So, in 1995, 10,000 yen was worth approximately $111 USD

The difference is 111 - 40 = 71

The closest/best answer is C

Cheers,
Brent