Answer:
6 of x and 5 of y
Explanation:
x = number of closets of the first type
y = number of closets of the second type
1200 = 100x + 120y
100 = 10x + 8y
10x = 100 - 8y
10x(100 - 8y) + 120y = 1200
1000 - 80y + 120y = 1200
40y = 200
y = 5
100 = 10x + 8×5 = 10x + 40
60 = 10x
x = 6
20x + 24y = max
20×6 + 24×5 = 120 + 120 = 240