PSLE Tommy and Daniel have the same total number of coins. Tommy has a number of ten-cent coins and 57 five-cent coins. The total mass of his coins is 1.245 kg. Daniel has a number of ten-cent coins and 117 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 3.8 g heavier than each five-cent coin. What is the total mass of Daniel's coins in kg?
(a)
Since Tommy has less five-cent coins than Daniel but both had the same number of coins, Tommy had more money.
Both boys have the same number of coins. Since Tommy has less five-cent coins than Daniel, it means that Tommy has more ten-cent coins than Daniel. So Tommy has more money.
Difference in the number of five-cent coins.
= 117 - 57
= 60
Difference in the value of 1 five-cent coin and 1 ten-cent coin
= 10 - 5
= 5¢
Amount that Tommy had more than Daniel
= 60 x 5
= 300¢
= $3
(b)
Difference in the mass between 60 five-cent coins and 60 ten-cent coins
= 60 x 3.8
= 228 g
= 0.228 kg
Total mass of Daniel's coins
= 1.245 - 0.228
= 1.017 kg
Answer(s): (a) Tommy, $3; (b) 1.017 kg