A piece of work can be done by 16 men in 8 days working 12 hours a day. How many men are needed to complete another work, which is three times the first one, in 24 days working 8 hours a day?
A bank offers 10% compound interest per half year. A customer deposits Rs. 2000 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