Explanation:

Solution:
profit % = 16(2/3)% = 1/6. So CP = 6, and SP = 6+1 = 7
Discount = 25% = 1/4 So MP = 4, SP = 4-1 = 3
Make S.P Same in both cases
C.P…. S.P…….. M.P
18……. 21……… 28
Difference between CP and MP is 10
So 10/18*100 = 55.55%