PSLE
Gabriel and Luke have the same total number of coins. Gabriel has a number of fifty-cent coins and 30 five-cent coins. The total mass of his coins is 0.358 kg. Luke has a number of fifty-cent coins and 70 five-cent coins.

1. Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
2. Each fifty-cent coin is 1.5 g heavier than each five-cent coin. What is the total mass of Luke's coins in kg?

(a)
Since Gabriel has less five-cent coins than Luke but both had the same number of coins, Gabriel had more money.

Both boys have the same number of coins. Since Gabriel has less five-cent coins than Luke, it means that Gabriel has more fifty-cent coins than Luke. So Gabriel has more money.

Difference in the number of five-cent coins.
= 70 - 30
= 40

Difference in the value of 1 five-cent coin and 1 fifty-cent coin
= 50 - 5
= 45¢

Amount that Gabriel had more than Luke
= 40 x 45
= 1800¢
= $18

(b)
Difference in the mass between 40 five-cent coins and 40 fifty-cent coins
= 40 x 1.5
= 60 g
= 0.06 kg

Total mass of Luke's coins
= 0.358 - 0.06
= 0.298 kg

Answer(s): (a) Gabriel, $18; (b) 0.298 kg