Average Quants Exercise I


Ques 1


The average age of 14 girls and their teacher's age is 15 years. If the teacher's age is excluded, the average reduces by 1. What is the teacher's age?

  a) 32 years
  b) 30 years
  c) 29 years
  d) 35 years


c is the correct option

Let's assume that the teacher's age is x. The total age of the 14 girls is 14 * 15 years = 210 years.
So, the total age of the 14 girls and the teacher is 210 + x years.
If the teacher's age is excluded, the average reduces by 1, so the average age of the 14 girls is 15 - 1 = 14 years.
So, the total age of the 14 girls is 14 * 14 years = 196 years.
Now, we can use the equation:
(14 * 14 + x) / 15 = 15
Expanding and solving for x, we get:
196 + x = 15 * 15
196 + x = 225
x = 225 - 196
x = 29
So, the teacher's age is 29 years, and the correct answer is c) 29 years.




Ques 2


There are 100 students in 3 sections A, B, and C of a class. The average mark of all the 3 sections was 84. The average of B and C was 87.5 and the average mark of A is 70. The number of students in A was

  a) 20
  b) 25
  c) 35
  d) 30


a is the correct option




Ques 3


The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is

  a) 29.5 Kg
  b) 35 Kg
  c) 32 Kg
  d) 31 Kg


d is the correct option




Ques 4


The average weight of five persons sitting in a boat is 38 kg. The average weight of the boat and the persons sitting in the boat is 52kg. What is the weight of the boat ?

  a) 232 Kg
  b) 242 Kg
  c) 122 Kg
  d) 218 Kg


c is the correct option




Ques 5


The average of two numbers is 8 and the average of other three numbers is 3. The average of the five numbers is

  a) 3
  b) 6
  c) 5
  d) 2


c is the correct option




Ques 6


The average of 11 results is 50. If the average of the first six results is 49 and that of the last six is 52, the sixth no. is

  a) 50
  b) 56
  c) 52
  d) 48


b is the correct option




Ques 7


The average age of six members of a family is 40 years. If the age of a guest is included, then the average age increases by 12.5%. What is the age (in years) of the guest?

  a) 75
  b) 79
  c) 45
  d) 95


d is the correct option