7. An investor deposits an amount of Rx per month in an account with a bank. His account is credited with interest at 6% p.a. effective. After making 60 monthly deposits he discontinues making any further deposits. At the end of 11 years the amount in his account, including interest is R10 000. Find Rx if: (a) Payments are made at the end of the month. (b) Payments are made at the beginning of the month.

An investor deposits an amount of Rx per month in an account with a bank. His account is credited with interest at 6% p.a. effective. After making 60 monthly deposits he discontinues making any further deposits. At the end of 11 years the amount in his account, including interest is R10000. Find Rx if: (a) Payments are made at the end of the month. (b) Payments are made at the beginning of the month