Sam saved RM 3,000 in an account which offered r% simple interest per annum on 15 February 2022. If the interest obtained on 1 April 2022 was RM 25, find: (a) the exact time of the investment (b) the value of r using the Baker's Rule. Eighteen months ago, a sum of money was invested. Now the investment is worth RM 10,900 . If the investment is extended for another 20 months, it will become RM 11,900. Find the original principal and the simple interest rate that was offered