Rakesh and Tessa were asked to find an explicit formula for the sequence 100, 50, 25,12.5. Rakesh said the formula is f(n)=100*(1/2)^n-1, and tessa said the formula is f(n)=200*(1/2)^n. Which one of them is right?

200*(1/2)^n

Step-by-step explanation:

This question can be solved by substituting the value of n= 1,2,3,4 in the both of the expression as there are four terms in the series.

For first expression 100*(1/2)^n-1

Thus formula 200*(1/2)^n correctly expresses the sequence  100, 50, 25,12.5

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you

step-by-step explanation: