PSLE
Dylan and Flynn have the same total number of coins. Dylan has a number of fifty-cent coins and 38 ten-cent coins. The total mass of his coins is 0.438 kg. Flynn has a number of fifty-cent coins and 58 ten-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 2.4 g heavier than each ten-cent coin. What is the total mass of Flynn's coins in kg?

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

Difference in the number of ten-cent coins.
= 58 - 38
= 20

Difference in the value of 1 ten-cent coin and 1 fifty-cent coin
= 50 - 10
= 40¢

Amount that Flynn had less than Dylan
= 20 x 40
= 800¢
= $8

(b)
Difference in the mass between 20 ten-cent coins and 20 fifty-cent coins
= 20 x 2.4
= 48 g
= 0.048 kg

Total mass of Flynn's coins
= 0.438 - 0.048
= 0.39 kg

Answer(s): (a) Dylan, $8; (b) 0.39 kg