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 40 g	$0.80	$0.70
	Every additional 10 g or part thereof	$0.30

How much did Jade pay for the postage when she sent a letter which weighed 65 g and 7 postcards to Indonesia by airmail?
Remaining mass that Jade had to pay for the letter as it was more than 40 g
= 65 - 40
= 25 g

Number of sets of additional 10 g of the letter that Jade had to pay for 
= 25 ÷ 10
= 2 r 5

Total number of sets of additional 10 g of the letter that Jade had to pay for 
= 2 + 1
= 3

Amount that Jade had to pay for the sets of additional 10 g of the letter
= 3 x 0.30
= $0.90

Total amount that Jade had to pay for the letter
= 0.80 + 0.90
= $1.70

Amount that Jade had to pay for the 7 postcards
= 7 x 0.70
= $4.90

Total amount that Jade paid
= 1.70 + 4.90
= $6.60

Answer(s): $6.60