PSLE George and Neave have the same total number of coins. George has a number of twenty-cent coins and 48 ten-cent coins. The total mass of his coins is 1.864 kg. Neave has a number of twenty-cent coins and 108 ten-cent coins.
- Who has less money in coins? How much less? Give your answers in this format. (Eg Adam, $12)
- Each twenty-cent coin is 3.1 g heavier than each ten-cent coin. What is the total mass of Neave's coins in kg?
(a)
Both boys have the same number of coins. Since Neave has more ten-cent coins than George, it means that Neave has less twenty-cent coins than George. So Neave has less money.
Difference in the number of ten-cent coins.
= 108 - 48
= 60
Difference in the value of 1 ten-cent coin and 1 twenty-cent coin
= 20 - 10
= 10¢
Amount that Neave had less than George
= 60 x 10
= 600¢
= $6
(b)
Difference in the mass between 60 ten-cent coins and 60 twenty-cent coins
= 60 x 3.1
= 186 g
= 0.186 kg
Total mass of Neave's coins
= 1.864 - 0.186
= 1.678 kg
Answer(s): (a) George, $6; (b) 1.678 kg