PSLE The airmail rates to two countries are shown. Tammy sent a letter weighing 57g to Indonesia and a letter weighing 11g to Sweden by airmail. How much did she pay altogether?
Mass |
Indonesia |
Sweden |
First 20g |
$0.65 |
$1.80 |
Every additional 10g |
$0.25 |
$0.60 |
Mass of the letter to Indonesia excluding the first 20 g
= 57 - 20
= 37 g
Sets of additional 10 g of the letter to Indonesia
= 37 ÷ 10
= 3 r 7
Sets of additional 10 g and part thereof the letter to Indonesia
= 3 + 1
= 4
Amount that Tammy paid for the letter to Indonesia
= 0.65 + 4 x 0.25
= 0.65 + 1.00
= $1.65
Amount that Tammy paid altogether
= 1.65 + 1.80
= $3.45
Answer(s): $3.45