5th grade math
posted by Karli .
I need help with this problem..the answer and how you got it. thanks
amy gets 1 hour for lunch at her job. today she used 1/4 hour to eat and 2/5 hour to run an errand. she spent the rest of her lunchtime writing a letter. how may minutes did amy spend writhing the letter?

1/4 + 2/5
We need the common denominator.
1/4 = 5/20
2/5 = 8/20
5/20 + 8/20 = 13/20
13/20 * 60 = 780/20 = 39 minutes
60  39 = 21 minutes
You could also change 1/4 hour to 15 minutes and 2/5 hour to 24 minutes and then add.