PSLE The airmail rates to two countries are shown. Xylia sent a letter weighing 99g to Thailand and a letter weighing 39g to Australia by airmail. How much did she pay altogether?
Mass |
Thailand |
Australia |
First 40g |
$0.95 |
$1.50 |
Every additional 20g |
$0.75 |
$0.45 |
Mass of the letter to Thailand excluding the first 40 g
= 99 - 40
= 59 g
Sets of additional 20 g of the letter to Thailand
= 59 ÷ 20
= 2 r 19
Sets of additional 20 g and part thereof the letter to Thailand
= 2 + 1
= 3
Amount that Xylia paid for the letter to Thailand
= 0.95 + 3 x 0.75
= 0.95 + 2.25
= $3.20
Amount that Xylia paid altogether
= 3.20 + 1.50
= $4.70
Answer(s): $4.70