SOLUTION: Tom is painting a fence, but he's taking his time. There are 100 feet of fence to paint, but he only paints 50% of the unpainted fence each day. How many feet has he painted after

Algebra ->  Sequences-and-series -> SOLUTION: Tom is painting a fence, but he's taking his time. There are 100 feet of fence to paint, but he only paints 50% of the unpainted fence each day. How many feet has he painted after       Log On


   

Question 867799: Tom is painting a fence, but he's taking his time. There are 100 feet of fence to paint, but he only paints 50% of the unpainted fence each day. How many feet has he painted after 4 days.
I wanted to know how to use a formula to solve this equation (explicit formula)
Thank You
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
first day 1/2= 50
second day 1/4=25
third day 1/8=12.5
fourth day 1/16=6.25
8/16+4/16 +2/16 +1/16=15/16
50.00+25.00+12.50+6.25=93.75 ft after 4 days
S=T1*(1 - r^n)/(1 - r)
S=50*(1 - 1/2^4)/(1 - 1/2)=93.75