PSLE Wesley and Ken have the same total number of coins. Wesley has a number of twenty-cent coins and 68 ten-cent coins. The total mass of his coins is 0.545 kg. Ken has a number of twenty-cent coins and 128 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 2.5 g heavier than each ten-cent coin. What is the total mass of Ken's coins in kg?
(a)
Since Wesley has less ten-cent coins than Ken but both had the same number of coins, Wesley had more money.
Both boys have the same number of coins. Since Wesley has less ten-cent coins than Ken, it means that Wesley has more twenty-cent coins than Ken. So Wesley has more money.
Difference in the number of ten-cent coins.
= 128 - 68
= 60
Difference in the value of 1 ten-cent coin and 1 twenty-cent coin
= 20 - 10
= 10¢
Amount that Wesley had more than Ken
= 60 x 10
= 600¢
= $6
(b)
Difference in the mass between 60 ten-cent coins and 60 twenty-cent coins
= 60 x 2.5
= 150 g
= 0.15 kg
Total mass of Ken's coins
= 0.545 - 0.15
= 0.395 kg
Answer(s): (a) Wesley, $6; (b) 0.395 kg