PSLE The airmail rates to two countries are shown. Erika sent a letter weighing 55g to Phillippines and a letter weighing 14g to Australia by airmail. How much did she pay altogether?
Mass |
Phillippines |
Australia |
First 20g |
$0.65 |
$1.60 |
Every additional 10g |
$0.25 |
$0.70 |
Mass of the letter to Phillippines excluding the first 20 g
= 55 - 20
= 35 g
Sets of additional 10 g of the letter to Phillippines
= 35 ÷ 10
= 3 r 5
Sets of additional 10 g and part thereof the letter to Phillippines
= 3 + 1
= 4
Amount that Erika paid for the letter to Phillippines
= 0.65 + 4 x 0.25
= 0.65 + 1.00
= $1.65
Amount that Erika paid altogether
= 1.65 + 1.60
= $3.25
Answer(s): $3.25