Price of present -> 100u

Jane paid 30% -> 30u

Ken paid 40% × 70u = 28u

Leon paid (100u – 30u – 28u)  = 42u

Jane paid 30u = $36

1u = 36 ÷ 30 = $1.20

New price of present -> $1.20 × 100 = $120

(a) Original price of present -> $120 ÷ 1.25 = $96

(b) Leon paid 42 × $1.20 = $50.40