PSLE
George and Sam have the same total number of coins. George has a number of twenty-cent coins and 63 five-cent coins. The total mass of his coins is 0.585 kg. Sam has a number of twenty-cent coins and 83 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 1.4 g heavier than each five-cent coin. What is the total mass of Sam's coins in kg?

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

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

Difference in the number of five-cent coins.
= 83 - 63
= 20

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

Amount that George had more than Sam
= 20 x 15
= 300¢
= $3

(b)
Difference in the mass between 20 five-cent coins and 20 twenty-cent coins
= 20 x 1.4
= 28 g
= 0.028 kg

Total mass of Sam's coins
= 0.585 - 0.028
= 0.557 kg

Answer(s): (a) George, $3; (b) 0.557 kg