Question $3$ Following is the time$-$line of a monthly cash flow with the interest rate is j$\_12=6\%$ p$.$a$.$

$($a$)$ Find the Future value of the cash flow if X$=$Y$=$$ $100.$

$($b$)$ Find the future value of the cash flow if X$=120,$ Y$=150.$

$($c$)$ Suppose the future value of this cash flow is $$1,220.$ Fid the size of payment Y if

X $=80.[5$ marks$],220$ and find the size of Y if X is $80?$