The Wilsons are establishing a Registered Educational Savings Plan $($RESP$)$ for their newborn

daughter. They would like to accumulate $$100,000$ in $18$ years by making bi$-$weekly $($every $2$

weeks$)$ deductions from their bank account. The bank estimates that they should be able to earn

$6\mathrm{.}5\%$ annual interest on this plan.

$($a$)$ How much must they deduct every $2$ weeks to achieve this goal?

$($b$)$ In total, how much interest has been earned in the plan over the $18$ years?