PSLE
Luke and Liam have the same total number of coins. Luke has a number of ten-cent coins and 63 five-cent coins. The total mass of his coins is 1.701 kg. Liam has a number of ten-cent coins and 83 five-cent coins.

1. Who has less money in coins? How much less? Give your answers in this format. (Eg Adam, $12)
2. Each ten-cent coin is 3.8 g heavier than each five-cent coin. What is the total mass of Liam's coins in kg?

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

Difference in the number of five-cent coins.
= 83 - 63
= 20

Difference in the value of 1 five-cent coin and 1 ten-cent coin
= 10 - 5
= 5¢

Amount that Liam had less than Luke
= 20 x 5
= 100¢
= $1

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

Total mass of Liam's coins
= 1.701 - 0.076
= 1.625 kg

Answer(s): (a) Luke, $1; (b) 1.625 kg