Question

Lisa finished her math assignment in 1/3 hours. Then she completed her history assignment in 3/8 hours. What was the total amount of time Lisa spent doing these two assignments?

Answer 1

17/24 hours

Explanation:

First, find the common denominator.

multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24

multiples of 8: 8, 16, 24

24 is the common number both 3 and 8 have and will be used as the denominator.

`(1)/(3) =(x)/(24)`

3 goes 8 times into 24, so you know you have to multiply the numerator and denominator by 8.

`(1)/(3) *(8)/(8)`

`=(8)/(24)`

`(3)/(8) =(x)/(24)`

You can multiply 8 three times to get 24. So, you know you have to multiply the numerator and denominator by 3.

`(3)/(8) *(3)/(3)`

`=(9)/(24)`

Now, you have
`(8)/(24)` and , so you must add them together.

`(8)/(24) +(9)/(24)`

`=(17)/(24)`

So, the answer is
`(17)/(24)` hours.