lets use divide and conquer method. basically option elimintation method in which we eliminate the wrong options.
so in option b and d they mentioned 7 cups, now as given each cup takes 3 pounds clay so 7 cups will need 7×3 = 21 pounds of claybut unfortunately we have only 20 pounds of clay. so Option B and D got eliminated.
now calculate profit for option A and C.
let assume c is number of cup and p is number of plates
equation can be
total clay = 3c + 2p
and total clay must be less than and equal to 20
3c + 2p <= 20
total profit = 2c + 3p
now for option A
3×2 + 2×7 = 20 equation satisfied
profit = 2×2 + 3×7= 25
for option C
3×0 + 8×2 = 16 <= 20 eauation satisfies.
profit = 2×0 + 8×3 = 24
so profit is in option A
