1.Five years ago, Paul had saved RM10,000 in an account that pays 6% compounded monthly. Now, he intends to add another X ringgit into the account. Find the value of X if the account will amount to RM30,000 in 10 years' time.

2.A debt of RM30,000 is due in two years and another of RM40,000 in five years. If the debtor wants to settle these two debts by making a single payment after three years, what is the single payment, assuming money is worth 8% compounded annually?

3.A debt of RM5,000 matures in two years and another of RM10,000 in five years. If the debtor wants to settle his debts by making two equal payments, one now and another in three years' time, find these payments, assuming money is worth 5% compounded monthly.

4.Harold has two debts: Rm5,000 due in two years and another RM3,000 due in four years. If Harold wishes to settle the two debts 3years from now, find this single payment if money is worth 8% compounded quarterly.

Can you explain to me the formula. Thanks