Write the situation as a simultaneous eqution:
x+y=87
10x+5y=545
Now solve for y by multiplying the whole of the first equation by the coefficient of x:
10x+10y=870
10x+5y=545
5y=325
y=65 nickels in the box
x+y=87
x=22 dimes in the box
To prove this is correct, we do (10 x 22)+(5 x 65)=545 cents ($5.45)
A unit cubes measures a distance of one on each side. The cube are then counted in a way to allow calculation of the volume visually.
The answer is 245 remainder 17
