Fill in the missing facts from the fact family3•3=9

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?

At $1.32 million, they closed last month percent above what they paid in 2007." how much did they pay in 2007?

A50% increase followed by 33 1/2% decrease