PSLE
Japheth and Lee have the same total number of coins. Japheth has a number of fifty-cent coins and 42 five-cent coins. The total mass of his coins is 0.584 kg. Lee has a number of fifty-cent coins and 62 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 1.8 g heavier than each five-cent coin. What is the total mass of Lee's coins in kg?

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

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

Difference in the number of five-cent coins.
= 62 - 42
= 20

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

Amount that Japheth had more than Lee
= 20 x 45
= 900¢
= $9

(b)
Difference in the mass between 20 five-cent coins and 20 fifty-cent coins
= 20 x 1.8
= 36 g
= 0.036 kg

Total mass of Lee's coins
= 0.584 - 0.036
= 0.548 kg

Answer(s): (a) Japheth, $9; (b) 0.548 kg