Question

The ratio of Zimba's current weight to his weight 3 years ago is 5 to 4. In pounds, what did Zimba weigh 3 years ago if he has gained 3.5 pounds since then?

Answer 1

14 pounds

Explanation:

Let C denote Zimba's current weight and A his weight 3 years ago. We are given the ratio:
`$(C)/(A)=(5)/(4)$` as well as
`$C=A+3.5$`. We substitute for C in the first equation to find:
`\[(A+3.5)/(A)=(5)/(4).\]` Multiplying both sides by 4A to clear denominators, we have:
`\[4A+14=5A.\]`

Finally we subtract 4A from both sides and find
`$A=\boxed{14}$` pounds.

Hope this helped! :)

Answer 2

3.5 pounds gained

from 4 to 5 units is change of 1 unit
3.5lb=1 unit

4 units=3 years ago
4*3.5=14

he weighed 14lb three years ago

14lb is answer