Let x represent the original price of the laptop. If $220 represents 20% of the original price, then x is to 100% as 220 is to 20%:
[tex]\frac{x}{100}=\frac{220}{20}[/tex]
Solve for x:
[tex]x=\frac{220}{20}\times100=1100[/tex]
Therefore, the original cost of the laptop was $1100.
