PSLE The airmail rates to two countries are shown. Xandra sent a letter weighing 55g to Thailand and a letter weighing 15g to Canada by airmail. How much did she pay altogether?
Mass |
Thailand |
Canada |
First 20g |
$0.55 |
$1.90 |
Every additional 10g |
$0.35 |
$0.65 |
Mass of the letter to Thailand excluding the first 20 g
= 55 - 20
= 35 g
Sets of additional 10 g of the letter to Thailand
= 35 ÷ 10
= 3 r 5
Sets of additional 10 g and part thereof the letter to Thailand
= 3 + 1
= 4
Amount that Xandra paid for the letter to Thailand
= 0.55 + 4 x 0.35
= 0.55 + 1.40
= $1.95
Amount that Xandra paid altogether
= 1.95 + 1.90
= $3.85
Answer(s): $3.85