Question

A baby gains 11 pounds in its first year of life. The baby gained 4 1/4 pounds during the first four months and 3 1/2 pounds in its second four months. How much did the baby gain in the last four months.

Answer 1

The baby gains 3.25lbs in the last 4 months.

This problem can be solved by simple subtraction. Take the total amount and subtract the 4 month increments in order to find the find 4 months.

Total = 1st 4 months + 2nd 4 months + 3rd 4 months

11 = 4.25 + 3.5 + 3rd 4 months

11 = 7.75 + 3rd 4 months

3.25 = 3rd 4 months