What's the formula for determining an outcome when dealing with progressive addition?

Question

 If you start with zero as your balance and each day add 5 + the total balance to make a new balance then repeat each day. How many days to get a balance of 40,000?

Answer 1

 

Let n - number of days need

 

    

Since we are adding $5 daily, 5n is the amount added in n days

 

 

    y = 5n is our formula

 

To find the number of days needed to accumulate $40,000

 

   40,000 = 5n

 

   40,000/5 = 5n/5

   

   8,000 = n

 

It will take 8,000 days to accumulate 40,000