Miscellaneous (Railway Maths)

Total Questions: 34

21. From certain number of apples, a man sells 1/3 of the apples to the first customer. He sells 1/2 of the remaining apples to the second customer, and 1/3 of the remaining apples plus 5 to the third customer. He then finds himself left with 3 apples. How many apples did the man have initially? [RRB NTPC 14/03/2021 (Evening)]

Correct Answer: (c) 36
Solution:

22. If the price of Bitcoin increases at the rate of one dollar every 20 seconds, then by how many dollars does the price of Bitcoin increase in half an hour? [RRB NTPC 01/04/2021 (Evening)]

Correct Answer: (c) $90
Solution:

23. There are 20 pigeons, 10 cows, 15 dogs and some buffaloes. If the total number of feet is 125 more than the heads, then what is the number of buffaloes? [RRB NTPC 03/04/2021 (Morning)]

Correct Answer: (c) 10
Solution:

24. What is the value of k in the following Arithmetic progression? 15 + 13 + 11 + 9 + ... + k = -105 [RRB NTPC 08/04/2021 (Evening)]

Correct Answer: (c) -25
Solution:

25. In a competition, two points are awarded for a win, one point for a draw, and no points for a loss. Fischer played 20 matches in which he drew three matches, lost at least one, and won at least one match. What will be his maximum and minimum possible marks respectively? [RRB NTPC 23/07/2021 (Morning)]

Correct Answer: (c) 35 and 5
Solution:

Maximum points = 16 win + 3 draw +1 lost = 32 + 3 = 35 points
Minimum points = 1 win + 3 draw + 16 lost = 2 + 3 = 5 points

26. If 9 × log(x) = log (9) + log (27) + log (81), then x = ? [RRB NTPC 24/07/2021 (Morning) ]

Correct Answer: (d) 3
Solution:

27. A certain number of women went to a hotel. Each woman spent as many rupees as one-fourth of the number of women. If the total bill paid was Rs. 20,449, then how many women visited the hotel? [RRB NTPC 31/07/2021 (Morning) ]

Correct Answer: (a) 286
Solution:

28. Arun and Sekhar have certain amounts of money. If Arun gives Rs. 30 to Sekhar, then Sekhar will have twice the amount left with Arun. If Sekhar gives Rs. 10 to Arun, then Arun will have thrice as much as is left with Sekhar. What amount (in Rs.) does each of Arun and Shekhar respectively have in the beginning ? [RRB NTPC 31/07/2021 (Evening) ]

Correct Answer: (d) 62, 34
Solution:

29. If A, B are two mutually exclusive events, then find P(A ∪ B). [RRB JE 30/05/2019 (Evening)]

Correct Answer: (a) P(A) + P(B)
Solution:

30. A boy was asked to write the value of (2)⁵ × (8)². He wrote it as 2582. Find the difference between the obtained and the actual value. [RRB JE 31/05/2019 (Evening)]

Correct Answer: (d) 534
Solution: