Mark and rock climbing-mathematics functions?

Question

Mark starts a rock climb when he is 1 mile above sea level. He can climb at the rate of 1.5 miles per hour. Which of the following functions would express Mark's height above sea level over time?

1. f(x) = 1.5x

2. f(x) = 1 + 1.5x

3. f(x) = 2.5x

Answer 1

2

Answer 2

2. f(x) = 1 + 1.5x

Answer 3

2. f(x)=1+1,5x

Here 1is starting point

1.5- climbing speed.