PSLE The airmail rates to two countries are shown. Natalie sent a letter weighing 91g to Phillippines and a letter weighing 33g to Canada by airmail. How much did she pay altogether?
Mass |
Phillippines |
Canada |
First 40g |
$0.75 |
$1.80 |
Every additional 20g |
$0.55 |
$0.80 |
Mass of the letter to Phillippines excluding the first 40 g
= 91 - 40
= 51 g
Sets of additional 20 g of the letter to Phillippines
= 51 ÷ 20
= 2 r 11
Sets of additional 20 g and part thereof the letter to Phillippines
= 2 + 1
= 3
Amount that Natalie paid for the letter to Phillippines
= 0.75 + 3 x 0.55
= 0.75 + 1.65
= $2.40
Amount that Natalie paid altogether
= 2.40 + 1.80
= $4.20
Answer(s): $4.20