Question

Shryia read a 480 page long book cover to cover in a single session, at a constant rate. After reading for 1.5 hours, she had 402 pages left to read. Let P(t) denote the number of pages to read P as a function of time t (measured in hours). Write the function's formula.

Answer 1

Answer: The function formula is,

P(t) = 480 - 48 t

Step-by-step explanation:

Since, initial number of pages = 480,

After 1.5 hours, the number of pages = 402,

Hence, the pages read by him in 1.5 hours = 480-402=72,

⇒ His constant speed of reading = $\frac{72}{1.5}$ = 48,

⇒ The pages he read in t hours = 48 t

Since, The pages left to read in t hours = Initial pages - The pages he read in t hours,

⇒ P(t) = 480 - 48 t

Which is the required function.

Answer 2

The correct answer is P(t)=-52t+480.  Hope this helped.