please answer this a and b both related manually not using excel

a. Given the present value of a RM3000 investment at the end of 3 years plus a RM6000 investment at the end of 6 years is RM7118.51. Calculate the effective annual rate of interest, i. (5 Marks) b. Maria can receive one of the following two payment streams: () RM600 at time 0, RM X at time n, and RM900 at time 2n. (ii) RM3000 at time 3n. At an annual effective interest rate of i, the present value of the 2 streams are equal. Given (1 + i)"= 0.785, calculate X. (5 Marks) [Total: 10 Marks]