PSLE
Daniel and Glen have the same total number of coins. Daniel has a number of fifty-cent coins and 30 five-cent coins. The total mass of his coins is 1.221 kg. Glen has a number of fifty-cent coins and 50 five-cent coins.

1. Who has less money in coins? How much less? Give your answers in this format. (Eg Adam, $12)
2. Each fifty-cent coin is 3.5 g heavier than each five-cent coin. What is the total mass of Glen's coins in kg?

(a)
Both boys have the same number of coins. Since Glen has more five-cent coins than Daniel, it means that Glen has less fifty-cent coins than Daniel.  So Glen has less money.

Difference in the number of five-cent coins.
= 50 - 30
= 20

Difference in the value of 1 five-cent coin and 1 fifty-cent coin
= 50 - 5
= 45¢

Amount that Glen had less than Daniel
= 20 x 45
= 900¢
= $9

(b)
Difference in the mass between 20 five-cent coins and 20 fifty-cent coins
= 20 x 3.5
= 70 g
= 0.07 kg

Total mass of Glen's coins
= 1.221 - 0.07
= 1.151 kg

Answer(s): (a) Daniel, $9; (b) 1.151 kg