Answer:
The equation is:

After

Explanation:
This situation can be represented by an exponential growth equation of the form

Where a is the initial amount
b is the growth rate
t is the time in months
In this case the initial amount is $ 3. Then

if she initially saves $3 and plans to double the amount she saves each month then

The bike Jane wants is $1,536 at the local bike shop.
Then

The equation is:

Now we solve the equation for t





