Answer:
20
Step-by-step explanation:
1) 5 feet is 60 inches
2)Divide 60 inches (total inches in one stack) by the 3 inches ( inches in the Average book)
3) 60/3=<u>20</u>
<span>15/7 is the best number which completes both equations.If 5/7Ă·1/3 then it becomes 5/7 X 3/1 where 1/3 in denominator becomes 3/1 so that the value is 15/7 then 15/7 multiplied by 1/3 which yields 5/7.So we derive the final answer 5/7.This result involves only simple multiplication and division.</span>
-7 and -6 would equal both