Question

The function h(t) = 210 – 15t models the altitude of a hot air balloon over time t, in minutes. Explain what h(10) means in the context of the real-world scenario, and how to find its value.

Answer 1

h(10) represents the altitude of the hot air balloon after 10 minutes' change. In this case, at the beginning, the hot air balloon is at an altitude of 210, unit unknown, every minute it decreases by 15. 
h(10)=210-15*10=60
10 minutes later it is at an altitude of 60

Answer 2

 t represents time, which is the input of the function, so we know that 10 is the time in minutes. h(t) represents the altitude, which is the output of the function after time, t. So, we need to substitute 10 into 210 – 15t in place of t. Simplifying 210 – 15(10), we get  that 60 is the altitude in feet. So, after 10 minutes, the hot air balloon is at 60 feet.