Answer:
5 $20 bills and 7 $10 bills
Step-by-step explanation:
You need to have 12 bills, and their values must add up to $170. Start with a guess, and adjust the guess until you find the answer.
The total number of $20 bills and $10 bills must be 10.
I made a table below. I started with a guess and kept adjusting it.
Number of Number of Total
$20 bills $10 bills Value
8 ($160) 4 ($40) $200 Value is too high.
6 ($120) 6 ($60) $180 Value is close
5 ($100) 7 ($70) $70 Correct value
Answer: 5 $20 bills and 7 $10 bills