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

Question : 1

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 : 2

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 : 3

The average of marks of 28 students in Mathematics was 50; 8 students left the school, then this average increased by 5. What is the average of marks obtained by the students who left the school ?

a) 37.5

b) 42.5

c) 50.5

d) 45

Question : 4

The average weight of 40 children of a class is 36.2 kg. When three more children with weight 42.3 kg, 39.7 kg and 39.5 kg join the class, the average weight of the 43 children in the class is

a) 36.5 kg

b) 38.35 kg

c) 39.2 kg

d) 37.3 kg

Question : 5

The average of five numbers is 7. When three new numbers are included, the average of the eight numbers becomes 8.5. The average of the three new numbers is

a) 10.5

b) 11

c) 9

d) 11.5

Question : 6

Average weight of 25 students of a class is 50 kg. If the weight of the class teacher is included, the average is increased by 1 kg. The weight of the teacher is

a) 77 kg

b) 74 kg

c) 76 kg

d) 75 kg