Seven years ago, the average age of A, B and C was 51 years. If A is 3 years older than B and B is 3 years older then C then the present ages of A, B and C are ( in year)
A bank offers 15% compound interest per half year. A customer deposits Rs 2400 each on 1st January and 1st July of a year. At the end of the year, the amount he would have gained by way of interest is