White paper costs 8¢
Explanation:
The only difference between the two purchases is 3 pins which made the price 15¢ more. Each pin is worth 5¢. We can create an equation with this:
3p + 4w =47¢
P is the price of the pins and w is the price of the paper.
We know p is 5¢
Plug in 5
15+4w=47
Subtract 15 from both sides
4w=32
Divide both sides by 4 to get the variable alone
W=8
The white paper costs 8¢
