Mean, Median & Mode (Railway Maths) (Part – V)

Total Questions: 20

1. if ⁿC₃ = ⁿC₈, then find n. [RRB NTPC 26/07/2021 (Evening) ]

Correct Answer: (d) 11
Solution:

2. Find the median of the discrete values. (a + 4), (a - 3.5), (a - 2.5), (a - 3), (a - 2), (a + 0.5), (a + 5) and (a - 0.5). [RRB JE 27/05/2019 (Afternoon) ]

Correct Answer: (c) a - 1.25
Solution:

3. Ten observations written in descending order are 45, 34, 32, 30, 2x - 13, x + 1, 17, 15, 14 and 8. If the median is 24, then find 'x'. [RRB JE 28/05/2019 (Morning) ]

Correct Answer: (b) 20
Solution:

4. Find the standard deviation of the first 'n' natural numbers. [RRB JE 02/06/2019 (Afternoon) ]

Correct Answer: (a)
Solution:

5. If the mid value of a class is 20 and the width of the class is 5, find the lower and upper limits of the class. [RRB JE 02/06/2019 (Evening)]

Correct Answer: (b) 17.5 - 22.5
Solution:

6. The mean of x, x + 3, x + 5, x + 7, x + 10 is 9. What is the mean of the first 3 observations? [RRB JE 28/06/2019 (Evening)]

Correct Answer: (b) 6.66
Solution:

7. The mean of 1, 4, 9, X, 12, 14, 15 and 16 is 10. Find the mode. [ALP Tier II 21/01/2019 (Afternoon)]

Correct Answer: (c) 9
Solution:

8. Find the mean of first 100 natural numbers? [ALP Tier II 21/01/2019 (Afternoon)]

Correct Answer: (c) 50.5
Solution:

9. Find the mean of 2, 5, 8, 14, 21? [ALP Tier II 21/01/2019 (Morning)]

Correct Answer: (b) 10
Solution:

10. If the median of the numbers 9, 15, 1, 15, 14, 9, 4 and x is 11, then find the value of x. [ALP Tier II 23/01/2019 (Afternoon)]

Correct Answer: (b) 13
Solution: