The weights of 4 boxes are 20, 30, 40 and 60 kilograms. Which of the following cannot be the total weight, in kilograms, of any combination of these boxes and in a combination a box can be used only once?
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