PSLE
Flynn and Oscar have the same total number of coins. Flynn has a number of ten-cent coins and 60 five-cent coins. The total mass of his coins is 0.396 kg. Oscar has a number of ten-cent coins and 100 five-cent coins.

1. Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
2. Each ten-cent coin is 1.6 g heavier than each five-cent coin. What is the total mass of Oscar's coins in kg?

(a)
Since Flynn has less five-cent coins than Oscar but both had the same number of coins, Flynn had more money.

Both boys have the same number of coins. Since Flynn has less five-cent coins than Oscar, it means that Flynn has more ten-cent coins than Oscar. So Flynn has more money.

Difference in the number of five-cent coins.
= 100 - 60
= 40

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

Amount that Flynn had more than Oscar
= 40 x 5
= 200¢
= $2

(b)
Difference in the mass between 40 five-cent coins and 40 ten-cent coins
= 40 x 1.6
= 64 g
= 0.064 kg

Total mass of Oscar's coins
= 0.396 - 0.064
= 0.332 kg

Answer(s): (a) Flynn, $2; (b) 0.332 kg