PSLE
George and Rael have the same total number of coins. George has a number of fifty-cent coins and 30 twenty-cent coins. The total mass of his coins is 0.927 kg. Rael has a number of fifty-cent coins and 70 twenty-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 2.6 g heavier than each twenty-cent coin. What is the total mass of Rael's coins in kg?

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

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

Difference in the number of twenty-cent coins.
= 70 - 30
= 40

Difference in the value of 1 twenty-cent coin and 1 fifty-cent coin
= 50 - 20
= 30¢

Amount that George had more than Rael
= 40 x 30
= 1200¢
= $12

(b)
Difference in the mass between 40 twenty-cent coins and 40 fifty-cent coins
= 40 x 2.6
= 104 g
= 0.104 kg

Total mass of Rael's coins
= 0.927 - 0.104
= 0.823 kg

Answer(s): (a) George, $12; (b) 0.823 kg