model 6 find average of excluded number Section-Wise Topic Notes With Detailed Explanation And Example Questions

Question : 1

The average of six numbers is 32. If each of the first three numbers is increased by 2 and each of the remaining three numbers is decreased by 4, then the new average is

a) 34

b) 31

c) 35

d) 30

Question : 2

The average of five numbers is 7. If three new numbers would be added, then the new average comes out to be 8.5. What is the average of those three new numbers?

a) 10.5

b) 11

c) 9

d) 11.5

Question : 3

If the mean of 4 observations is 20, when a constant 'C’ is added to each observation, the mean becomes 22. The value of C is :

a) –2

b) 2

c) 6

d) 4

Question : 4

The average of five numbers is 140. If one number is excluded, the average of the remaining four numbers is 130. The excluded number is :

a) 134

b) 180

c) 135

d) 150

Question : 5

The mean weight of 34 students of a school is 42 kg. If the weight of the teacher be included, the mean rises by 400 grams. Find the weight of the teacher (in kg).

a) 57 kg

b) 66 kg

c) 55 kg

d) 56 kg

Question : 6

There are 50 students in a class. Their average weight is 45 kg. When one student leaves the class the average weight reduces by 100g. What is the weight of the student who left the class ?

a) 47.9 kg

b) 49.9 kg

c) 45 kg

d) 50.1 kg