PSLE The airmail rates to two countries are shown. Tina sent a letter weighing 79g to Phillippines and a letter weighing 10g to China by airmail. How much did she pay altogether?
Mass |
Phillippines |
China |
First 20g |
$0.55 |
$1.70 |
Every additional 10g |
$0.15 |
$0.55 |
Mass of the letter to Phillippines excluding the first 20 g
= 79 - 20
= 59 g
Sets of additional 10 g of the letter to Phillippines
= 59 ÷ 10
= 5 r 9
Sets of additional 10 g and part thereof the letter to Phillippines
= 5 + 1
= 6
Amount that Tina paid for the letter to Phillippines
= 0.55 + 6 x 0.15
= 0.55 + 0.90
= $1.45
Amount that Tina paid altogether
= 1.45 + 1.70
= $3.15
Answer(s): $3.15