PSLE John and Julian have the same total number of coins. John has a number of ten-cent coins and 47 five-cent coins. The total mass of his coins is 0.537 kg. Julian has a number of ten-cent coins and 87 five-cent coins.
- Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
- Each ten-cent coin is 1.2 g heavier than each five-cent coin. What is the total mass of Julian's coins in kg?
(a)
Since John has less five-cent coins than Julian but both had the same number of coins, John had more money.
Both boys have the same number of coins. Since John has less five-cent coins than Julian, it means that John has more ten-cent coins than Julian. So John has more money.
Difference in the number of five-cent coins.
= 87 - 47
= 40
Difference in the value of 1 five-cent coin and 1 ten-cent coin
= 10 - 5
= 5¢
Amount that John had more than Julian
= 40 x 5
= 200¢
= $2
(b)
Difference in the mass between 40 five-cent coins and 40 ten-cent coins
= 40 x 1.2
= 48 g
= 0.048 kg
Total mass of Julian's coins
= 0.537 - 0.048
= 0.489 kg
Answer(s): (a) John, $2; (b) 0.489 kg