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

So 11 pounds for the whole first year. 4 1/4 + 3 1/2 = 7 3/4 so 11 - 7 3/4 = 3 1/4 in the last four months

Answer 2

Find out the how much did the baby gain in the last four months.

To prove

Let us assume that the baby gain in the last four months be x .

As given

A baby gains 11 pounds in its first year of life.

`The\ baby\ gained\ 4(1)/(4)during\ first\ four\ months.`

i.e

`The\ baby\ gained\ (17)/(4)\ during\ first\ four\ months.`

`The\ baby\ gained\ 3(1)/(2)during\ second\ four\ months.`

i.e

`The\ baby\ gained\ (7)/(2)\ during\ second\ four\ months.`

Than the equation becomes

`x + (17)/(4) + (7)/(2) = 11`

`x = 11 -(17)/(4) - (7)/(2)`

L.C.M (4,2) = 4

`x = (44 - 17 - 7*2)/(4)`

solving

`x = (44 - 17 - 14)/(4)`

`x = (13)/(4)`

or written as in the mixed fraction.

`x = 3(1)/(4)\ pounds`

x = 3.25 pounds the baby gain in the last four months .