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

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.