A man buys a watch for Rs.1950 in cash and sells it for Rs. 2200 at a credit of 1 year.If the rate of interest is 10% per annum,the man :  Choose the correct choice
A) gains Rs. 55
B) gains Rs. 50
C) loses Rs. 30
D) gains Rs. 30
E) None of these
Solution   S.P. = P.W. of Rs. 2200 due 1 year hence = Rs. [ 2200x100/100 + (10x 1) ]= Rs. 2000.   ∴ Gain = Rs. (2000 - 1950) = Rs. 50.   Answer gains Rs. 50
<result>B</result>
A man buys a watch for Rs.1950 in cash and sells it for Rs. 2200 at a credit of 1 year.If the rate of interest is 10% per annum,the man :