there are 36 quarters.
Let the number of nickels be x
Let the number of quarters be y
Value Value
Type Number of of
of of EACH ALL
coin coins coin coins
-------------------------------------------
nickels x $0.05 $0.05x
quarters y $0.25 $0.25y
-------------------------------------------
TOTALS 52 ----- $3.60
The first equation comes from the second column.
x + y = 11
The second equation comes from the last column.
0.05x + 0.25y = 3.60
Get rid of decimals by multiplying every term by 100:
5x + 25y = 360
So we have the system of equations:
x+y=52
5x+25y=360
We solve by substitution. Solve the first equation for y:
x + y = 52
y = 52 - x
Substitute (52 - x) for y in 5x + 25y = 360
5x + 25(52 - x) = 360
5x + 1300 - 25x = 360
-20x + 1300 = 360
-20x = -940
x = = 5 the number of nickels.
Substitute in y = 52 - x
y = 52 - (5
y = 47 quarters.
The number of quarters is 52-x or 52-5 or 47 quarters.