Chapter 8, Problem 16CCSR

To determine

To Find: The score would student receive for correctly answering 15 questions.

Answer to Problem 16CCSR

The score for 15 correct answers will be 75.

Explanation of Solution

Given information:

The score on a history test varies directly with the number of questions the student correctly answer. A student who correctly answer 14 questions receives a score of 70.

Since, the score of history test (S) varies directly proportional to number of questions attempted correctly (C) then,

  $S=kC$

Here, k is proportionality constant.

The value of k is calculated as follows.

For question correctly attempted 14 the score is 70, so

  $\begin{array}{l}70=k·14\hfill \\ k=\frac{70}{14}\hfill \\ k=5\hfill \end{array}$

Thus, the equation becomes,

  $S=5·C$

Now, calculate the score for 15 correct answers,

  $\begin{array}{l}{S}_{15}=5\times 15\\ =75\end{array}$

Hence, the score for 15 correct answers will be 75.