PSLE
George and Michael have the same total number of coins. George has a number of twenty-cent coins and 60 five-cent coins. The total mass of his coins is 1.55 kg. Michael has a number of twenty-cent coins and 80 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 3.8 g heavier than each five-cent coin. What is the total mass of Michael's coins in kg?

(a)
Since George has less five-cent coins than Michael 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 Michael, it means that George has more twenty-cent coins than Michael. So George has more money.

Difference in the number of five-cent coins.
= 80 - 60
= 20

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

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

(b)
Difference in the mass between 20 five-cent coins and 20 twenty-cent coins
= 20 x 3.8
= 76 g
= 0.076 kg

Total mass of Michael's coins
= 1.55 - 0.076
= 1.474 kg

Answer(s): (a) George, $3; (b) 1.474 kg