PSLE
Perry and Wesley have the same total number of coins. Perry has a number of ten-cent coins and 30 five-cent coins. The total mass of his coins is 0.612 kg. Wesley has a number of ten-cent coins and 70 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 1.1 g heavier than each five-cent coin. What is the total mass of Wesley's coins in kg?

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

Difference in the number of five-cent coins.
= 70 - 30
= 40

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

Amount that Wesley had less than Perry
= 40 x 5
= 200¢
= $2

(b)
Difference in the mass between 40 five-cent coins and 40 ten-cent coins
= 40 x 1.1
= 44 g
= 0.044 kg

Total mass of Wesley's coins
= 0.612 - 0.044
= 0.568 kg

Answer(s): (a) Perry, $2; (b) 0.568 kg