PSLE Vaidev and Caden have the same total number of coins. Vaidev has a number of fifty-cent coins and 57 twenty-cent coins. The total mass of his coins is 0.6 kg. Caden has a number of fifty-cent coins and 117 twenty-cent coins.
- Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
- Each fifty-cent coin is 1.6 g heavier than each twenty-cent coin. What is the total mass of Caden's coins in kg?
(a)
Since Vaidev has less twenty-cent coins than Caden but both had the same number of coins, Vaidev had more money.
Both boys have the same number of coins. Since Vaidev has less twenty-cent coins than Caden, it means that Vaidev has more fifty-cent coins than Caden. So Vaidev has more money.
Difference in the number of twenty-cent coins.
= 117 - 57
= 60
Difference in the value of 1 twenty-cent coin and 1 fifty-cent coin
= 50 - 20
= 30¢
Amount that Vaidev had more than Caden
= 60 x 30
= 1800¢
= $18
(b)
Difference in the mass between 60 twenty-cent coins and 60 fifty-cent coins
= 60 x 1.6
= 96 g
= 0.096 kg
Total mass of Caden's coins
= 0.6 - 0.096
= 0.504 kg
Answer(s): (a) Vaidev, $18; (b) 0.504 kg