PSLE The airmail rates to two countries are shown. Rachel sent a letter weighing 72g to Vietnam and a letter weighing 21g to Canada by airmail. How much did she pay altogether?
Mass |
Vietnam |
Canada |
First 30g |
$0.65 |
$1.90 |
Every additional 15g |
$0.25 |
$0.85 |
Mass of the letter to Vietnam excluding the first 30 g
= 72 - 30
= 42 g
Sets of additional 15 g of the letter to Vietnam
= 42 ÷ 15
= 2 r 12
Sets of additional 15 g and part thereof the letter to Vietnam
= 2 + 1
= 3
Amount that Rachel paid for the letter to Vietnam
= 0.65 + 3 x 0.25
= 0.65 + 0.75
= $1.40
Amount that Rachel paid altogether
= 1.40 + 1.90
= $3.30
Answer(s): $3.30