Question

Carlos wants to practice piano 2 hours each day. He practices piano for 3/4 hour before school and 7/10 hour when he gets home. How many hours has Carlos practiced piano? How much longer does he need to practice before going to bed in order to meet his goal?

Answer 1

Carlos has practiced piano for
`(29)/(20)=1(9)/(20)` hours.

Carlos needs to practice
`(11)/(20)` hours.

Explanation:

We have been given that Carlos wants to practice piano 2 hours each day. He practices piano for 3/4 hour before school and 7/10 hour when he gets home.

First of all, we will find piano practiced before school and after school by adding both amounts as:

`(3)/(4)+(7)/(10)`

Make a common denominator:

`(3*5)/(4*5)+(7*2)/(10*2)`

`(15)/(20)+(14)/(20)`

Add numerators:

`(15+14)/(20)`

`(29)/(20)`

Therefore, Carlos has practiced piano for
`(29)/(20)` hours.

Now, we will subtract
`(29)/(20)` from 2 find number of hours Carlos needs to practice to reach his goal.

`2-(29)/(20)`

`(2*20)/(20)-(29)/(20)`

`(40)/(20)-(29)/(20)`

`(40-29)/(20)`

`(11)/(20)`

Therefore, Carlos needs to practice
`(11)/(20)` hours before going to bed in order to meet his goal.