Question

a sell a book to B at a profit of 5% and B sells it to C at profit of 10% if C pays 231 for it what did it cost A?

Answer 1

Let the cost price of book for A = ₹ X

Hence, SP for A = CP(100 + g)/100 = CP for B

or, Cost price for B = x(100+5)/100 = 21x/20

again, SP for B = 21x/20((100 + 10)/100) = CP for C

or, CP for C = (21x/20)(11/10) = ₹ 231 (Given)

or x = ₹ 200

Hence, Cost Price of book for A = ₹ 200