Tim worked on his science fair project about volcanoes for one hour. He spent 15 minutes on decorating his display board and 20 minutes testing his volcano demonstration. What fraction of the hour did tim spend on his display board and volcano, (i need some help on this one)

30/60 or 1/2

Step-by-step explanation:

we have a total of an hour, which is 60 minutes.

he spent 15 on decorating, so d=15

he spent 20 on testing, so t=20.

the question is asking for the total of both of these times. so d + t is 20 plus 15.

that would be 35.

so, we know that he spent 30 minutes on decoeating and testing. he bad 60 total minutes. so, 30/60. simplify, and we get 1/2. he spend half of his time decorating and testing.

341

step-by-step explanation:

all you have to do is 9x31 (which equals 279) and then 20x31 (which equals 620). then you have to subtract. 620-279=341.