Peter has 4 more $50 bills than $10 bills in his wallet. If the total amount of money in his wallet is $380, how many $10 bills does Peter have?
I know the answer but I don't know how to set up the equation.
Let x = # of $50 bills
Let y = # of $10 bills
x = 4+y
50x + 10y = 380
substitute 4 + y for x
50(4+y) + 10y = 380
200 + 50y + 10y = 380
Solve for y to find # of 10 dollar bills.
Let the number of $10 bills be x.
Let the number of $50 bills be x+4.
Now, lets form a equation.
10x+50(x+4)= 380 (Equation)
-> 10x is the number of $10 bills we will get.
-> 50(x+4) is how many $50 which will be helpful for finding the $10.
-> $380 is the total of 10x and 50(x+4)
Lets go back to the formed equation.
10x+50(x+4)= 380
10x+50x+200=380
60x+200=380
60x=380-200
60x=180
x=180/60 (Cut the zeros)
x=18/6
x=3
Ans) Peter has 3 $10 bills.