Here ,The average of five numbers = 140
Sum of five numbers = 5 × 140
If one number is excluded, then
The average of five numbers = 130
Sum of five numbers = 4 × 130
Required number = 5 × 140 – 4 × 130
Required number = 700 – 520 = 180
Second method to solve this question with the help of given formula :
Here, y = (140 – 130) = 10 , n = 5
Excluded number = Average + y (n – 1)

Correct Option: C

Here ,The average of five numbers = 140
Sum of five numbers = 5 × 140
If one number is excluded, then
The average of five numbers = 130
Sum of five numbers = 4 × 130
Required number = 5 × 140 – 4 × 130
Required number = 700 – 520 = 180
Second method to solve this question with the help of given formula :
Here, y = (140 – 130) = 10 , n = 5
Excluded number = Average + y (n – 1)
Excluded number = 140 + 10 × 4 = 180

Let the new observation be y.
The average of 6 observations = 45.5.

Correct Option: B

Let the new observation be y.
The average of 6 observations = 45.5.

Suppose the initial expenditure per day = y

Correct Option: D

Suppose the initial expenditure per day = y

Given that , The average weight of 50 students = 45 kg.
Total weight of 50 students = 50 × 45
On leaving the class by one student the average weight reduces by = 100 gm
Total weight of 49 students = 49 × 44.9

Correct Option: C

Given that , The average weight of 50 students = 45 kg.
Total weight of 50 students = 50 × 45
On leaving the class by one student the average weight reduces by = 100 gm
Total weight of 49 students = 49 × 44.9
∴ Weight of the student who left = 50 × 45 – 49 × 44.9
Weight of the student who left = 2250 – 2200.1 = 49.9 kg.

Here , The average of 50 numbers = 38.
If two numbers namely 45 and 55 are discarded , then

Correct Option: C

Here , The average of 50 numbers = 38.
If two numbers namely 45 and 55 are discarded , then