 # Average (6)

1. The average age of 36 students in a group is 14 years. When teacher’s age is included to it, the average increases by one. Find out the teacher’s age in years?
1. 51 years
2. 49 years
3. 53 years
4. 50 years

Explanation :-

Age of the teacher = (37 * 15) – (36 * 14) years = 51 years.

2. The average of five numbers id 27. If one number is excluded, the average becomes 25. What is the excluded number?
1. 30
2. 40
3. 32.5
4. 35

Explanation :-

Excluded Number = (5*27) – (4*25) = 135 – 100 = 35

3. The batting average for 40 innings of a cricket player is 50 runs. His highest score exceeds his lowest score by 172 runs. If these two innings are excluded, the average of the remaining 38 innings is 48 runs. Find out the highest score of the player.
1. 150
2. 174
3. 180
4. 166

Explanation :-

Total runs in 40 innings = 40 × 50
Total runs in 38 innings = 38 × 48
Sum of the scores of the excluded innings = (40 × 50) – (38 × 48) = 2000 – 1824 = 176
Let the lowest runs be x (in excluded innings)
Therefore ,  Highest runs = x + 172
x + x + 172 = 176
2x = 4
x = 2
Highest runs = x + 172 = 2 + 172 = 174

4. The average score of a cricketer for ten matches is 38.9 runs. If the average for the first six matches is 42, what is the average for the last four matches?
1. 34.25
2. 36.4
3. 40.2
4. 32.25

Explanation :-

Average Score of 10 Matches = 38.9
Average of the last 4 matches = 42
Also ,
[(38.9 ×10) – (42 × 6)] / 4 = (1216 − 750) / 34.25

5. The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then
1. None of these
2. x = y + z
3. 2x = y + z
4. x = 2y + 2z