Functions question (investment scenarios using f(t) and g(t))

[Xibu4]

I'm having trouble identifying my variables in this question, more specifically r and n. At first I though r and n were obviously 2 and 6 respectfully, but then I took a look at the 2nd function and noticed that r must be 0.8 ? Is this a typo or am I making a silly error.

 

[BigBeachBanana]

View attachment 35256
I'm having trouble identifying my variables in this question, more specifically r and n. At first I though r and n were obviously 2 and 6 respectfully, but then I took a look at the 2nd function and noticed that r must be 0.8 ? Is this a typo or am I making a silly error.

How do you know they're the same r?

Based on the numbers, I agree with you but r=2 -> 200% interest rate which is unrealistic.