The table shows the airmail rates for sending letters and postcards to some countries.

Destination	Letters		Postcards
	Mass	Postage Rate	Per piece
Indonesia, Malaysia	1st 20 g	$0.90	$0.70
	Every additional 10 g or part thereof	$0.30

How much did Jen pay for the postage when she sent a letter which weighed 68 g and 5 postcards to Malaysia by airmail?
Remaining mass that Jen had to pay for the letter as it was more than 20 g
= 68 - 20
= 48 g

Number of sets of additional 10 g of the letter that Jen had to pay for 
= 48 ÷ 10
= 4 r 8

Total number of sets of additional 10 g of the letter that Jen had to pay for 
= 4 + 1
= 5

Amount that Jen had to pay for the sets of additional 10 g of the letter
= 5 x 0.30
= $1.50

Total amount that Jen had to pay for the letter
= 0.90 + 1.50
= $2.40

Amount that Jen had to pay for the 5 postcards
= 5 x 0.70
= $3.50

Total amount that Jen paid
= 2.40 + 3.50
= $5.90

Answer(s): $5.90