In this question, we are given that John's marks were wrongly entered as 83 instead of 63 and that the average marks for the whole class increased by half as a result.
We are asked to find the number of students in the class.
To solve this problem,
we can first assume the number of students in the class to be x.
We know that the total increase in marks for x students is x/2,
since the average increase is 1/2.
We can then use this information to find the value of x by setting up an equation using the given information.
Specifically, we can set up the equation x/2 = 83 - 63,
which gives us x = 40 students.
This means that there are 40 students in the class.

If the average of three consecutive even numbers is 34, 
and the first number is X, 
then the next two even numbers would be X+2 and X+4. 
Using this information, 
we can set up the following two equations:
Apti Average 17 = 34
Apti Average 18 = 34
Solving these equations for X, we find that X = 32. 
Therefore, the largest of the three numbers is X+4 = 32+4 = 36.

Let x be the average score of the batsman after the 17th inning.

Then the average score of the batsman after the 16th inning is (x - 3).

The total number of runs scored by the batsman in the first 16 innings is (x - 3) * 16 + 87 = 17x.

Solving for x, we get x = (87 - 48) / 17 = 39

The average of the different possible weights of Varun is 67 kg.
To find this, we can use the following steps:
Let Varun's weight be X kg.
According to Varun, 65 < According to Varun's father, 60 < X < 70.
According to Varun's sister, X <= 68.
The different possible weights of Varun, or the values that satisfy all of these conditions, are 66, 67, and 68.
The average of these weights is (66 + 67 + 68) / 3 = 201 / 3 = 67 kg.

To find the average of the first 40 natural numbers,
the sum of these numbers is calculated using the formula
"sum of first n natural numbers=n(n+1)/2",
which yields a sum of 820.
The average is then calculated by dividing this sum by the total number of numbers,
resulting in an average of 20.5

Solution

Total age 4 members,10 years ago=(24×4)=96

Total age of 4 members now=(98+10×4)=136

Total age of 6 members now=(24×6)=144

Sum of the ages of 2 children=(144-136)=8 years

The average of the first 4 consecutive even numbers is 5.
To find this, we can use the following steps:
The first 4 consecutive even numbers are 2, 4, 6, and 8.
The average of these numbers is (2 + 4 + 6 + 8) / 4 = 20 / 4 = 5.

To find the 13th result, given that the average of 25 results is 18, 
the average of the first 12 results is 14, 
and the average of the last 12 results is 17, 
we can first determine the sum of the 25 results.

This can be done by multiplying the average of the results by the total number of results, as follows:

Sum of results = 18 * 25 = 450

We can then determine the sum of the first 12 results by multiplying the average of these results by the number of results, as follows:

Sum of first 12 results = 14 * 12 = 168

Similarly, 
we can determine the sum of the last 12 results by multiplying the average of these results by the number of results, as follows:

Sum of last 12 results = 17 * 12 = 204

The 13th result is then equal to the sum of the 25 results minus the sum of the first 12 results and the last 12 results, or:

13th result = 450 - (168 + 204) = 450 - 372 = 78

6th result = (58*6+63*6-60*11)=66

The sum of the ages of the two teachers is 62 years.
To find this, we can use the following steps:
The total age of the 30 boys is 450 years.
The total age of the 30 boys and the two teachers is 512 years.
Therefore, the sum of the ages of the two teachers is 512 - 450 = 62 years.