Sara bought some 6-penny nails and some 10-penny nails at Ace hardware. She bought 2 more 6-penny nails than she did 10-penny nails. She had a total of 8 nails. How many 6-penny and 10-penny nails did Sara purchase?

Solution:

6-penny nail: x+2

10-penny nail: x

x+2+x=8

x=3

So

6-penny nail: 5

10-penny nail: 3