A person lent certain sum of money at 5% per annum simple interest and in 15 years the interest amounted to Rs 250 less than the sum lent. What was thesum lent (in Rs)?
The average marks of 10 students in an examination was 25. It was later found that the marks of one student had been wrongly entered as 34 instead of 43. What is the correct average?
A bank offers 15% compound interest per half year. A customer deposits Rs 7200 each on 1st January and 1st July of a year. At the end of the year, the amount he would have gained by means of interest is