PSLE Neave and Ben have the same total number of coins. Neave has a number of twenty-cent coins and 57 ten-cent coins. The total mass of his coins is 0.235 kg. Ben has a number of twenty-cent coins and 117 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 2.2 g heavier than each ten-cent coin. What is the total mass of Ben's coins in kg?
(a)
Since Neave has less ten-cent coins than Ben but both had the same number of coins, Neave had more money.
Both boys have the same number of coins. Since Neave has less ten-cent coins than Ben, it means that Neave has more twenty-cent coins than Ben. So Neave has more money.
Difference in the number of ten-cent coins.
= 117 - 57
= 60
Difference in the value of 1 ten-cent coin and 1 twenty-cent coin
= 20 - 10
= 10¢
Amount that Neave had more than Ben
= 60 x 10
= 600¢
= $6
(b)
Difference in the mass between 60 ten-cent coins and 60 twenty-cent coins
= 60 x 2.2
= 132 g
= 0.132 kg
Total mass of Ben's coins
= 0.235 - 0.132
= 0.103 kg
Answer(s): (a) Neave, $6; (b) 0.103 kg