Answer:
0 $20 bills and 10 $5 bills
1 $20 bills and 6 $5 bills
2 $20 bills and 2 $5 bills
Step-by-step explanation:
Equations
Let's set:
x=number of $5 bills
y=number of $20 bills
The total amount Sara has is given by
5x+20y
And we know it's equal to $50, thus:
5x+20y=50
Dividing by 5
x+4y=10
We would need another condition to solve for x and y, but we can determine some combinations that solve the problem.
Solving for x:
x=10-4y
Since both x and y are integers and cannot be negative:
10-4y≥0
Swapping sides:
4y≤10
Dividing by 4:
y≤2.5
Thus, y can only have the values {0,1,2}
For y=0
x=10-4*0=10
x=10
For y=1
x=10-4*1=6
x=6
For y=2
x=10-4*2=2
x=2
Thus, the possible combinations are:
0 $20 bills and 10 $5 bills
1 $20 bills and 6 $5 bills
2 $20 bills and 2 $5 bills
