Data
• Promotion: 2%
,
• Monthly salary: $2601
Procedure
The original salary is 100% of the quantity, as the raise ($2601) is 102%. To solve this problem we have to build a relation between these quantities:

where x represents the quantity he was making before.
Multiplying both sides of the equation times 100%:
![100\%*\frac{x}{100\operatorname{\%}}=\frac{2,601}{102\operatorname{\%}}*100\%]()
![x=\frac{2,601}{102\operatorname{\%}}*100\%]()
Simplifying:
![x=\frac{260,100}{102\operatorname{\%}}]()
![x=\frac{260,100}{102\operatorname{\%}}=2550.0]()
Answer: $2250.0