Question

Ray is reading a book of 150 pages at a constant rate of 25 pages per hour. Let’s consider the following function: the pages left to read L as a function of time passed since the beginning of the reading T.

Tell what is the domain and the range of this function?

Answer 1

The domain is

`0 \leqslant x \leqslant 6`

The range is

`0 \leqslant y \leqslant 150`

where x is a natural number

Explanation:

The pages left to read L, as a function of time t is

L(T)=150-25T

If Ray finishes reading, then

150-25T=0

150=25T

T=6

In 6 hours time Ray will finish reading

Therefore the domain is 0≤x≤6

The range is reading no page to reading all pages.

That's;

`0 \leqslant y \leqslant 150`