Question

Susan has p clean plates. After using 2/3 of the clean plates for a dinner party, Susan used 1/5 of the remaining plates to store the leftovers. In terms of p, how many plates are still clean and unused?

Answer 1

dinner: 2/3 p
leftovers: 1/5 (p - 2/3 p) = 1/15 p

total fraction used: 2/3 + 1/15 = 11/15

clean: 4/15 p