Question

Five students sit for an exam which has a maximum score of 100. The average of the five scores achieved by the students in the exam was 89. What could the minimum score be gained?

Answer 1

To find minimum, assume that everyone else got maximum.
Let the minimum score is x.
Other 4 scores are 100,100,100 and 100.

Given that mean is 89

$\frac{100+100+100+100+x}{5}=89\\ \\ \frac{400+x}{5}=89\\ \\ 400+x=89 \times 5\\ \\400+x=445\\ \\ x=445-400\\ \\x=45$

So minimum score that can be achieved is 45.

Answer 2

Answer:

Average of 5 scores achieved by 5 students = 89

 Total marks achieved by 5 students = 5 * 89 = 445

suppose 4 students scored the maximum of 100 marks, then the fifth student would have scored = 445 - 400 = 45

So 45 is the lowest score possible for any student.