Question

After taking four quizzes your average is 74 points out of 100 what must be your average be on the next five quizzes to increase your average up to 79 points

Answer 1

Answer: The average of the next five quizzes = 83.

Explanation:

Given : After taking 4 quizzes your average is 74 points out of 100.

Let q be the average of the next five quizzes.

Then , the total number of quizzes = 4+5=9

Since ,
`\text{Average}=\frac{\text{Sum of observations}}{\text{Number of observations}}`

Sum of observations = (Average) x (Number of observations)

i.e. Sum of first four quizzes = 74 (4)

Sum of next five quizzes = 5q

According to the question , we have

`79=(74(4)+5q)/(9)`

`\Rightarrow\ 711=296+5q\\\\\Rightarrow\ 5q=711-296\\\\\Rightarrow\ 5q=415\\\\\Rightarrow\ q=(415)/(5)\\\\\Rightarrow\ q=83`

Hence, the average of the next five quizzes = 83.