time=number of cuts times time it takes to make each cut
to cut something into 2 pieces, you need 1 cut
to cut into 3 pieces you need 2 cuts
therefor, to cut something into n pieces, it takes n-1 cuts
so 8piece is 8-1=7 cuts
time=number of cust times time per cut
time=7 times 5 minutes
times=35 minutes
