PSLE
Gabriel and Jeremy have the same total number of coins. Gabriel has a number of twenty-cent coins and 50 five-cent coins. The total mass of his coins is 0.844 kg. Jeremy has a number of twenty-cent coins and 70 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 3.7 g heavier than each five-cent coin. What is the total mass of Jeremy's coins in kg?

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

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

Difference in the number of five-cent coins.
= 70 - 50
= 20

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

Amount that Gabriel had more than Jeremy
= 20 x 15
= 300¢
= $3

(b)
Difference in the mass between 20 five-cent coins and 20 twenty-cent coins
= 20 x 3.7
= 74 g
= 0.074 kg

Total mass of Jeremy's coins
= 0.844 - 0.074
= 0.77 kg

Answer(s): (a) Gabriel, $3; (b) 0.77 kg