Jan has $130 if she saves 25 per week in how many weeks will she have $600

For this we can set up an equation where w is the amount of weeks, 130 is the starting amount and 600 is the total.

130+25w=600
        25w=470
         
            w=18.8

We will round 18.8 weeks to 19 weeks to make it a whole number. 
It takes 19 weeks to save $600.