Question

Nancy bought a mobile phone marked at $720 at a discount

Answer 1

20% of $720( original cost)= $144 (discount)
$720- $ 144 = $576 (discounted cost)
5% tax = $36 (tax payed)
tax + cost of phone = $612 (total of both tax and discounted cost)

20% of $612=$122.40 (deposit cost?)