The table shows the airmail rates for sending letters and postcards to some countries.
Destination |
Letters |
Postcards |
|
Mass |
Postage Rate |
Per piece |
Thailand, Vietnam, Myanmar
|
1st 40 g |
$1.60 |
$0.60
|
Every additional 10 g or part thereof |
$0.45 |
How much did Jen pay for the postage when she sent a letter which weighed 123 g and 9 postcards to Vietnam by airmail?
Remaining mass that Jen had to pay for the letter as it was more than 40 g
= 123 - 40
= 83 g
Number of sets of additional 10 g of the letter that Jen had to pay for
= 83 ÷ 10
= 8 r 3
Total number of sets of additional 10 g of the letter that Jen had to pay for
= 8 + 1
= 9
Amount that Jen had to pay for the sets of additional 10 g of the letter
= 9 x 0.45
= $4.05
Total amount that Jen had to pay for the letter
= 1.60 + 4.05
= $5.65
Amount that Jen had to pay for the 9 postcards
= 9 x 0.60
= $5.40
Total amount that Jen paid
= 5.65 + 5.40
= $11.05
Answer(s): $11.05