Let x be the number of $10 bills in Iago pocket.
1. If he has twice as many $1 bills as $10 bills, then he has (2x) $1 bills.
2. He has two fewer $20 bills than he does $10 bills, then he has (x-2) $20 bills.
3. He has three more $5 bills than $10 bills, then he has (x+3) $5 bills.
In total he has $160 that is x·10+2x·1+(x-2)·20+(x+3)·5.
Equate these two expressions and solve the equation:
Thus, he has
- 5 bills for $10;
- 10 bills for $1;
- 3 bills for $20;
- 8 bills for $5.