Average

Question 1

1. The numbers 2, 3, 5 and x have an average equal to 4. What’s the value of x? [BKB- Cash 2017)

A. 4
B. 6
C. 8
D. 10

Answer 1

6

Question 2

2. Selim gets grades of 79, 83, 86 and 89 on a four math tests. What grades must he get on his fifth test to average 85? [BB Cash officer-11]

A. 77
B. 66
C. 88
D. 99

Answer 2

88

Question 3

3. A student was asked to find the arithmetic mean of the numbers 3, 11, 7, 9,15, 13, 8, 19, 17, 21, 14 and x. He found the mean to be 12. What should be the number in the place of x? [BB cash 2016]

A. 3
B. 7
C. 17
D. 31

Answer 3

7

Question 4

4. The average of 2, 7, 6 and x is 5 and average of 18, 1, 6, x and y is 10. What is the value of y? [PKB]

A. 5
B. 10
C. 20
D. 30

Answer 4

A. 5

Question 5

5. The average of three numbers is 24, If the two of the numbers are 21 and 23, the 3rd number is- [Uttara Bank]

A. 32
B. 28
C. 48
D. 38

Answer 5

B. 28

Question 6

6. Ajit has a certain average for 9 innings. In the tenth innings, he scores 100 runs thereby increasing his average by 8 runs. His new average is:

A. 20
B. 21
C. 28
D. 32

Answer 6

Let Ajit's average be x for 9 innings. 
So, Ajit scored 9x run in 9 innings.
In the 10th innings, he scored 100 runs then average became (x+8). And he scored (x+8)*10 runs in 10 innings.
Now,
⇒9x+100=10×(x+8)
or, 9x+100=10x+80
or, x=100−80
or, x=20 New average=(x+8)=28runs

Question 7

7. The average temperature for Wednesday, Thursday and Friday was 40°C. The average for Thursday, Friday and Saturday was 41°C. If temperature on Saturday was 42°C, what was the temperature on Wednesday?

A. 39°C
B. 44°C
C. 38°C
D. 41°C

Answer 7

Answer: Option A

Question 8

8. The average of first five multiples of 9 is:

A. 20
B. 27
C. 28
D. 30

Answer 8

Answer: Option B

Question 9

9. Jerry’s average (arithmetic mean) score on the first 3 of 4 tests is 85. If Jerry wants to raise his average by 2 points, what score must he earn on the fourth test?

○ 87
○ 89
○ 90
○ 93
○ 95

Answer 9

93