Answer :
Whole one pizza = 1 = 5/5
Patrick ate on Friday 3/5 so 5/5-3/5=2/5
On Saturday P. ate 1/2 of 2/5 so = 1/2*2/5= 2/10=1/5
So deduct 1/5 from 2/5 and we have 1/5 left
Patrick ate on Friday 3/5 so 5/5-3/5=2/5
On Saturday P. ate 1/2 of 2/5 so = 1/2*2/5= 2/10=1/5
So deduct 1/5 from 2/5 and we have 1/5 left