Letitia has 7 1/6 yards of yellow ribbon, 5 1/4 yards of orange ribbon, and 5 1/6 yards of brown ribbion. how much ribbion does she have altogether

Bob paid $3 less than tim at a local pizza parlor. together they spent $7.80. how much did bob pay for pizza?

Ineed some on this. not sure how to solve.

#5 points possible: 3. total attempts: 5 using your calculator, find the range and standard deviation, round to two decimals places: the table below gives the number of hours spent watching tv last week by a sample of 24 children. 76 57 89 73 88 42 31 46 80 42 38 57 49 50 89 36 69 82 27 88 39 89 95 18 range = standard deviation =