$7\mathrm{.}3$ Allen invested an amount of R$20000$ on $1$ January $2015,$ at an interest rate of

$10,3\%$ p$.$a$.$ compounded monthly. At the start of the second year, he deposited R$15000$

into the same account but the interest rate increased to $11,5\%$ p$.$a$.$ compounded

monthly. At the end of the third year, he withdrew a certain amount of money from his

savings and kept the rest of the money in his account for a further $2$ years at an interest

rate of $16,8\%$ p$.$a$.$ compounded quarterly.

$7\mathrm{.}3\mathrm{.}1$ What was the balance of his investment on $31$ December $2015?$

$7\mathrm{.}3\mathrm{.}2$ How much money, to the nearest rand, did he withdraw at the end of the third

year, given that his final bank balance at the end of the fifth year was

R$30183,64?$