Jane needs $330 to buy a bicycle. She has $50 in savings.
She makes $40 each week babysitting.
a. Write an equation that can be used to find the number of weeks, w, Jane needs to work in order to buy the bicycle.

b. Solve the equation you wrote in part a. to find the number of weeks, w.

The bicycle is marked down by 25% after Jane has babysat for one week.

c. How many more weeks must Jane babysit in order to buy the bicycle? Show your work or explain how you know.