PSLE
Liam and Paul have the same total number of coins. Liam has a number of fifty-cent coins and 50 ten-cent coins. The total mass of his coins is 0.317 kg. Paul has a number of fifty-cent coins and 100 ten-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 2.9 g heavier than each ten-cent coin. What is the total mass of Paul's coins in kg?

(a)
Since Liam has less ten-cent coins than Paul but both had the same number of coins, Liam had more money.

Both boys have the same number of coins. Since Liam has less ten-cent coins than Paul, it means that Liam has more fifty-cent coins than Paul. So Liam has more money.

Difference in the number of ten-cent coins.
= 100 - 50
= 50

Difference in the value of 1 ten-cent coin and 1 fifty-cent coin
= 50 - 10
= 40¢

Amount that Liam had more than Paul
= 50 x 40
= 2000¢
= $20

(b)
Difference in the mass between 50 ten-cent coins and 50 fifty-cent coins
= 50 x 2.9
= 145 g
= 0.145 kg

Total mass of Paul's coins
= 0.317 - 0.145
= 0.172 kg

Answer(s): (a) Liam, $20; (b) 0.172 kg