If the number 1 on the clock is replaced by the letter M, the number 2 is replaced by N and so on, then when the time is 21:00 p.m. the hour hand will be at ____ letter
A sum of money was invested at the rate of 7.5% S.I. per annum for 4 years. If the investment was for 5 years, the interest earned would have been Rs. 375 more. What was the initial sum invested?