# Averages Problems for SSC CGL

421.

The average of 34 numbers is zero. Of them, at the most how many may be greater than zero?

A.) 34
B.) 35
C.) 32
D.) 33

Average of 34 numbers is = 0
Therefore sum of all 34 numbers = 0
It is quite possible that 33 of these numbers may be positive and if their sum is a then 34th number is (-a)

422.

There were 25 students in a particular Class. The class teacher knows the overall height of all the students in the class is 1400. Can you find the average height of students in the class?

A.) 56
B.) 58.8
C.) 61.6
D.) 53.2

Use the below formula to find the average height of students in the class
Average Height = ( Total Height of all students in the Class / Total Number of Students)
Average Height
= ( 1400 / 25)
= 56

423.

Present ages of Sameer and Anand are in the ratio of 5 : 4 respectively. Three years hence, the ratio of their ages will become 11 : 9 respectively. What is Anand's present age in years?

A.) 24
B.) 27
C.) 40
D.) Cannot be determined

Let the present ages of Sameer and Anand be 5x years and 4x years respectively.
Then, 5x+ 3 / 4x + 3 = 11/9 => 9(5x + 3) = 11(4x + 3) => 45x + 27 = 44x + 33
=> 45x - 44x = 33 - 27 => x = 6.
Anand's present age = 4x = 24 years.

424.

The average age of a group of 10 students was 26. The average age increased by 1 years when two new students joined the group. What is the average age of the two new students who joined the group?

A.) 22
B.) 32
C.) 21
D.) 41

The average age of a group of 10 students is 26.
Therefore, the sum of the ages of all 10 of them
= 10 × 26
= 260
When two students joins the group, the average increase by 1.
New Average = 27
Now there are 12 students Therefore, sum of all the ages of 12 students
= 12 × 27
= 324
Therefore, the sum of the ages of two students who joined
= 324 - 260
= 64
And the average age of these two students
= 64 / 2
= 32.

425.

Physics Teacher knows the average score of 33 students in her subject is 49.5. Can you help the physics teacher to find the overall marks obtained by all the students in her subject?

A.) 1551.83
B.) 1633.5
C.) 1796.85
D.) 1726.85