PSLE Michael and Simon have the same total number of coins. Michael has a number of twenty-cent coins and 65 ten-cent coins. The total mass of his coins is 0.369 kg. Simon has a number of twenty-cent coins and 85 ten-cent coins.
- Who has more money in coins? How much more? Give your answers in this format. (Eg Adam, $12)
- Each twenty-cent coin is 1.2 g heavier than each ten-cent coin. What is the total mass of Simon's coins in kg?
(a)
Since Michael has less ten-cent coins than Simon but both had the same number of coins, Michael had more money.
Both boys have the same number of coins. Since Michael has less ten-cent coins than Simon, it means that Michael has more twenty-cent coins than Simon. So Michael has more money.
Difference in the number of ten-cent coins.
= 85 - 65
= 20
Difference in the value of 1 ten-cent coin and 1 twenty-cent coin
= 20 - 10
= 10¢
Amount that Michael had more than Simon
= 20 x 10
= 200¢
= $2
(b)
Difference in the mass between 20 ten-cent coins and 20 twenty-cent coins
= 20 x 1.2
= 24 g
= 0.024 kg
Total mass of Simon's coins
= 0.369 - 0.024
= 0.345 kg
Answer(s): (a) Michael, $2; (b) 0.345 kg