Question

Turner is reading a 400-page book. He reads 4 pages every 5 minutes. The number of pages Turner has left to read after x minutes is represented by the function: f(x) = 400 - (4/5)x. What does the number 400 represent in this function?

A) The number of pages Turner has already read.
B) The number of pages Turner reads every 5 minutes.
C) The total number of pages in the book.
D) The time in minutes it took Turner to finish the book.

Answer 1

C) The total number of pages in the book.

Step-by-step explanation:

f(x) = 400 - (4/5)x

f(x) is the number of page LEFT to read. At x = 0, when he started, is 400. The (4/5)x is Turner's reading rate, in pages per minute, and x is the time he reads, in minutes. The term (4/5)x is subtracted from 400. 400 must be the number of pages in the book he is reading.

A) The number of pages Turner has already read.

B) The number of pages Turner reads every 5 minutes.

C) The total number of pages in the book.

D) The time in minutes it took Turner to finish the book.

Answer 2

The number 400 in the function represents the total number of pages in the book that Turner has yet to read when he begins.

Step-by-step explanation:

The number 400 in the function f(x) = 400 - (4/5)x represents option C, which is the total number of pages in the book Turner is reading. This can be seen from how the function is structured: as x, representing time in minutes, increases by 5, the number of pages Turner has left to read decreases by 4. The function starts at 400, indicating that Turner has all 400 pages to read at the start.