Question

A gym instructor has a total of 60 hand weight in her studio. Some of the hand weights are 3 pound weights and the rest are 5 pound weights. If there are 10 more 5-lb weights than 3-lb weights, then how many of each kind does she have?

Answer 1

• 35 5-lb weights
• 25 3-lb weights

Explanation:

Let t and f represent the numbers of three- and five-pound weights. The problem statement tells us ...

f + t = 60

f - t = 10

Adding these two equations, we get ...

(f +t) +(f -t) = (60) +(10)

2f = 70 . . . . . eliminate parentheses

f = 35 . . . . . . divide by 2

She has 35 5-lb weights, and 25 3-lb weights.