A trader sells a machine for $30,000, gaining 72% on his cost price. How much did he pay for the machine? What was his profit?

CP $ $17,441.86  Profit $12,558.14

let the cost price be100% and plus the gain is72%

=>172% is your sold price i.e. $30,000/-

=>100% i.e CP is ----?

==> C.P =  (100 *30000) /172 = $17,441.86

profit = S.P - C.P = $30,000 - $17,441.86 = $12,558.14.

Answer is option (C) CP $ $17,441.86  Profit $12,558.14

The answer is B.

Computation is as follows:

Cost =30,000 /1.72 =17,441.86

Profit =30,000-17,441.86 =12,558.14