PSLE
Rael and Bryan have the same total number of coins. Rael has a number of twenty-cent coins and 40 five-cent coins. The total mass of his coins is 0.348 kg. Bryan has a number of twenty-cent coins and 100 five-cent coins.

1. Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
2. Each twenty-cent coin is 2.7 g heavier than each five-cent coin. What is the total mass of Bryan's coins in kg?

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

Both boys have the same number of coins. Since Rael has less five-cent coins than Bryan, it means that Rael has more twenty-cent coins than Bryan. So Rael has more money.

Difference in the number of five-cent coins.
= 100 - 40
= 60

Difference in the value of 1 five-cent coin and 1 twenty-cent coin
= 20 - 5
= 15¢

Amount that Rael had more than Bryan
= 60 x 15
= 900¢
= $9

(b)
Difference in the mass between 60 five-cent coins and 60 twenty-cent coins
= 60 x 2.7
= 162 g
= 0.162 kg

Total mass of Bryan's coins
= 0.348 - 0.162
= 0.186 kg

Answer(s): (a) Rael, $9; (b) 0.186 kg