Question

Cindy invested $2,800. The function V(t) = 2,800(1.025)t models the value of Cindy’s investment after y months. The function S(t) = 10t models the amount of money that Cindy has saved in a safe at her house after t months. Which function C(t) models the combined value of the investment and money in the safe?

A. C(t) =2,800(1.025)t + 10t
B. C(t) = 2,800(1.025)11t
C. C(t) =(2,800 + 10t)(1.025)t
D. C(t) =2,810(1.025)t

Answer 1

Lets see

• V(t)=2800(1.025)^t
• S(t)=10t

Add both

• C(t)=S(t)+V(t)
• C(t)=2800(1.025)^t+10t

Answer 2

• Option A

Explanation:

The amounts invested and saved are independent and their total is the combined amount.

• 
  `C(t) = V(t) + S(t)`
• 
  `C(t) = 2,800(1.025)^t + 10t`

Correct choice is A