A model for the average typing speeds S (words per minute) of a typing student after t weeks of lessons is given by Find
A)96 words per minute
B)24 words per minute
C)52 words per minute
D)104 words per minute
E)16 words per minute

Question

A model for the average typing speeds S (words per minute) of a typing student after t weeks of lessons is given by  Find 
A)96 words per minute 
B)24 words per minute 
C)52 words per minute 
D)104 words per minute 
E)16 words per minute

Quizplus · Accepted Answer

In the given model, the term (t-4) implies that the student has already completed four weeks of lessons and the speed is increasing by 4 words per minute every week.

For t=4, the student has completed four weeks of lessons and the typing speed would be:

S(4) = 4(4) + 24 = 40 words per minute

For t=5, the student has completed five weeks of lessons and the typing speed would be:

S(5) = 4(5) + 24 = 44 words per minute

Similarly, for t=6, S(6) = 48 words per minute

Hence, the speed is increasing by 4 words per minute every week and the initial speed (for t=4) is 24 words per minute.

Therefore, the answer is (C) 52 words per minute, which is the typing speed for t=8 (four weeks of completed lessons plus four additional weeks according to the formula), i.e.,

S(8) = 4(8-4) + 24 = 52 words per minute.

A Model for the Average Typing Speeds S (Words Per