A baby gains 11 pounds in its first year of life. The baby gained 4 and one-fourth pounds during the first four months and 3 and one-halfpounds in its second four months. How much did the baby gain in the last four months?

Question

3 and one-fourthpounds
3 and one-halfpounds
4 pounds
5 pounds

Answer 1

To find out how much the baby gained in the last four months, we can start with the total weight gain in the first year and subtract the weight gains from the first eight months.

1. Total weight gain in the first year: 11 pounds

2. Weight gain in the first four months: \( 4 \frac{1}{4} \) pounds = 4.25 pounds

3. Weight gain in the second four months: \( 3 \frac{1}{2} \) pounds = 3.5 pounds

Now we can calculate the total weight gain for the first eight months: \[ 4.25 \text{ pounds} + 3.5 \text{ pounds} = 7.75 \text{ pounds} \]

Next, we subtract this amount from the total weight gain: \[ 11 \text{ pounds} - 7.75 \text{ pounds} = 3.25 \text{ pounds} \]

Now, converting 3.25 pounds back into a mixed number: \[ 3.25 \text{ pounds} = 3 \frac{1}{4} \text{ pounds} \]

Thus, the baby gained \(3 \frac{1}{4}\) pounds in the last four months. Therefore, the answer is:

3 and one-fourth pounds.