PSLE
George and Xavier have the same total number of coins. George has a number of fifty-cent coins and 47 twenty-cent coins. The total mass of his coins is 0.673 kg. Xavier has a number of fifty-cent coins and 97 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 3.5 g heavier than each twenty-cent coin. What is the total mass of Xavier's coins in kg?

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

Difference in the number of twenty-cent coins.
= 97 - 47
= 50

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

Amount that George had more than Xavier
= 50 x 30
= 1500¢
= $15

(b)
Difference in the mass between 50 twenty-cent coins and 50 fifty-cent coins
= 50 x 3.5
= 175 g
= 0.175 kg

Total mass of Xavier's coins
= 0.673 - 0.175
= 0.498 kg

Answer(s): (a) George, $15; (b) 0.498 kg