Percentage (Railway Maths) (Part – I)

Total Questions: 50

11. The sum of two numbers is 205. If one of these numbers is reduced by 5% and the other is increased by 10%, the resulting numbers are equal to each other. Find the smaller of the two initial numbers. [Group D 06/10/2022 (Morning) ]

Correct Answer: (a) 95
Solution:

12. If the length l of a room is reduced by 10% and breadth b is increased by 10%, then find the positive change in its perimeter. [Group D 11/10/2022 (Evening)]

Correct Answer: (a) (l − b) / 5
Solution:

13. Ravi has to go from Hyderabad to Delhi. The distance between Hyderabad and Delhi is 1,200 kms. He decides to travel 25% of the distance on foot , 30% of the distance by bus,and 15% of the distance by train and remaining distance by an airplane. What is the distance travelled by Ravi by an Airplane? [NTPC CBT II Level 5 (12/06/2022) Shift 1 ]

Correct Answer: (b) 360 km
Solution:

14. A and B are numbers such that A is 40% larger than B. If A is decreased by 20% and B is increased by 38% then what is the percentage increase in the total value of A and B? [NTPC CBT II Level 2 (13/06/2022) Shift 1 ]

Correct Answer: (b)
Solution:

15. The marks obtained by A in a test are 20% more than the marks obtained by B and C obtained 85% of the total marks obtained by A and B. By what percentage are the marks obtained by A less than the marks obtained by C ? (Correct to one decimal place) [NTPC CBT II Level 3 (14/06/2022) Shift 2 ]

Correct Answer: (a) 35.8%
Solution:

16. Total number of students in class X is 140 and the ratio of boys to girls is 2 : 3. If 50% of the boys and 33.33% of the girls are selected for competition in school, then find the percentage of unselected boys to unselected girls? [NTPC CBT II Level 5 (15/06/2022) Shift 3]

Correct Answer: (a) 50%
Solution:

17. In measuring the sides of a rectangle error of 10% and 8% in excess are made. Find the error percent in its area. [NTPC CBT II Level 2 (16/06/2022) Shift 2]

Correct Answer: (c) 18.8%
Solution:

18. What is to be added to 12% of 2400, so that the sum will be equal to 18% of 5400? [NTPC CBT I 28/12/2020 (Morning)]

Correct Answer: (c) 684
Solution:

19. In an examination, 55% candidates passed in English, 35% candidates passed in Mathematics and 20% candidates passed in both the subjects. If the total number of failed candidates in both the subjects is 1200, then find how many candidates took the exam. [NTPC CBT I 29/12/2020 (Morning)]

Correct Answer: (c) 4000
Solution:

20. In an examination, 41% of students failed in Economics, 35% of students failed in Geography and 39% of students failed in History. 5% of the students failed in all the three subjects, 14% of students failed in Economics and Geography, 21% of the students failed in Geography and History and 18% of students failed in History and Economics. Find the percentage of students who failed in only Economics. [NTPC CBT I 08/01/2021 (Morning)]

Correct Answer: (b) 14%
Solution: