A student decides she wants to save money to buy a used car, which costs $2600. She comes up with what she thinks is a very modest savings plan. She decides to save 2 cents the first day and double the amount she saves each day thereafter. On the second day she plans to save 4 cents, on the third day, 8 cents, and so on. Determine how long it will take her to save enough money to buy the car ?