26) If the number of quantities in group A is 10 and in group B is 8, and their individual average is 24 and 16 respectively, find the combined average of the two groups.
20.44
18.22
16.22
18.66
Answer: A
Explanation:
The combined average of the two groups is =
27) The average of square of first 6 consecutive even numbers is:
12.20
60.66
16.45
178
Answer: B
Explanation:
Here, n=6
So, Average = 2 (6+1) (2*6+1)/3
=2*7*13/3
= 182 /3
= 60.66
28) Find the average of first 4 consecutive even numbers.
2
5
1
8
Answer: B
Explanation:
Average of first n consecutive even numbers is given by:
Average= n+1
Here, n=4
So, the average = 4+1=5
29) Find the average of first 5 consecutive even numbers starting from 2 to 10, where the last even number is 10.
1
6
2
8
Answer: B
Explanation:
The average of first n consecutive even numbers starting from 2 to X, where the last even number is X, is given by:
= (X+2)/2
Here, X=10
So, the required average = (10+2)/2
= 12/2
=6
30) Find the average of the square of first 6 consecutive even numbers starting from 2 to 12, where the last even number is 12.
