How many pennies fit in a 22-inch circle?

Answer :

663 Pennies can fit into a 22-inch circle

Laptops are 1200 each and cameras are 500 each.

Using elimination:
3c+l=2700
5c+2l=4900

We will make the coefficients of l the same by multiplying the top equation by 2:
2(3c+l=2700)
6c+2l=5400

Our system is now
6c+2l=5400
5c+2l=4900

Subtract the bottom equation:
6c+2l=5400
-(5c+2l=4900)

We have
1c=500
So each camera is 500.

Substitute that in our original first equation:
3(500)+l=2700
1500+l=2700
1500+l-1500=2700-1500
l=1200