Answer:
the mixed fraction 9 3/4 means there are 9 4/4 s and one 3/4all togather there are 39/4 divid this by 3/4 to find the no of shifts. 39/4 ÷(3/4)
=39/4. ×4/3=13
13shifts
It is a combination, becasue the order does not matter
C (4,3) = 4! / [3! (4-3)!] = 4
Answer: A and C.
