$3-S.$ What is the present value of perpetuity of $$12,000$ to be received at the end of every year forever, discounted at $9\mathrm{.}4\%?$

Perpetuity Return

$3-$T$.$ What is the interest rate on a perpetuity that provides an annual payment of $$500$ and sells for $$5,000?$

$3-$U$.$ What is the interest rate on a perpetuity that provides an annual payment of $$120$ and sells for $$3,000?$