17) What is the profit % if the cost price of 16 bolts is equal to the selling price of 12 bolts?

18) What is the selling price if the cost price is Rs.7282/- with a profit of Rs.208?

19) What is the interest earned, if the principal is Rs.12000/- becomes to an amount of Rs.15600/-?

20) What is the principal amount deposited, if the maturity proceeds to an amount of Rs.25000/- and interest earned Rs.6000/-?

21) What is the interest earned, if the principal is for Rs.12500/- maturity becomes to a amount of Rs.17500/-?