Question

a music store gives every 20th customer a $5 gift card. Every 50th customer gets a $10 gift card. which customer will be the first to receive both types of gift cards?

Answer 1

20, 40, 60, 80, 100, 120, 140

50, 100, 150, 200

Answer 2

20=2*2*5
50=2*5*5
the first customer to receive both = 2*2*5*5=100 - that would be the smallest common multiple

Answer 3

100