PSLE The airmail rates to two countries are shown. Risa sent a letter weighing 66g to Thailand and a letter weighing 27g to Australia by airmail. How much did she pay altogether?
Mass |
Thailand |
Australia |
First 30g |
$0.75 |
$1.40 |
Every additional 15g |
$0.35 |
$0.50 |
Mass of the letter to Thailand excluding the first 30 g
= 66 - 30
= 36 g
Sets of additional 15 g of the letter to Thailand
= 36 ÷ 15
= 2 r 6
Sets of additional 15 g and part thereof the letter to Thailand
= 2 + 1
= 3
Amount that Risa paid for the letter to Thailand
= 0.75 + 3 x 0.35
= 0.75 + 1.05
= $1.80
Amount that Risa paid altogether
= 1.80 + 1.40
= $3.20
Answer(s): $3.20