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

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

Answer 2

Answer:

14 pounds

Step-by-step explanation:

Let C denote Zimba's current weight and A his weight 3 years ago. We are given the ratio: $\frac{C}{A}=\frac{5}{4}$  as well as $C=A+3.5$. We substitute for C in the first equation to find:  $\[\frac{A+3.5}{A}=\frac{5}{4}.\]$  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! :)