Question

The mean of 30 students is 42. Among them two got zero marks, then find the mean of remaining students...

Answer 1

Answer:

• Mean for the remaining students is 45.

Step-by-step explanation:

Given that:

• The mean of the marks of 30 students is 42.
• Among them two got zero marks.

To Find:

• Mean of the remaining students.

Solution:

As,

$\sf{Mean=\dfrac{Sum \;of\; terms}{Number\; of\; terms}}$

We can say that,

$\sf{Sum\;of\;terms=Mean\times Number\;of\;terms}$

Hence, as,

$\sf{42=\dfrac{Total\;marks}{30}}$

Therefore,

$\sf{Total\; marks=30\times42}$

$\sf{=1260}$

Thus, total marks is 1260.

Now,

As, two students got zero marks. So, they did not contribute any marks in the total marks. Hence, we can say 1260 marks was scored by (30 - 2) = 28 students.

Calculating mean for remaining 28 students,

As we know that,

$\sf{Mean=\dfrac{Sum \;of\; terms}{Number\; of\; terms}}$

Substituting the values,

$\sf{Mean=\dfrac{1260}{28}}$

Dividing the numbers,

$\sf{Mean=45}$

Hence,

• Mean for the remaining 28 students is 45.