Question

Ravi had some face masks. He sold 1/4 the face masks on Monday and 82 face masks on Tuesday. He then donated 2/5 of the remaining face masks to a nursing home and 120 face masks to some needy families. In the end, he had 108 face masks left. How much face masks did Ravi have at first?

Answer 1

number of masks ---- x
after Monday sale, masks left = (3/4)x or 3x/4
after Tuesday sale , masks left = 3x/4 - 82
after donaltion, maskes left = (3/5)(3x/4 - 82) - 120

(3/5)(3x/4 - 82) - 120 = 108
(3/5)(3x/4 - 82) = 228
3x/4 - 82 = 380
3x/4 = 462
x = 616