RRB NTPC Mathematics – Set 13

 

RRB NTPC Mathematics – Set 13

Q1. A can do a piece of work in 20 days and B can do the same work in 30 days. If they work together, how long will it take to complete the work?
A. 10 days
B. 12 days
C. 15 days
D. 18 days
✅ Answer: B. 12 days

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Q2. The least number which when divided by 5, 6, 7 and 8 leaves a remainder 3 in each case but is divisible by 9 is:
A. 1683
B. 3363
C. 2523
D. 1008
✅ Answer: B. 3363

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Q3. The average of first five multiples of 3 is:
A. 6
B. 9
C. 12
D. 15
✅ Answer: B. 9

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Q4. A train 120 meters long takes 10 seconds to cross a man running at 6 km/h in the same direction. Find the speed of the train.
A. 54 km/h
B. 60 km/h
C. 66 km/h
D. 72 km/h
✅ Answer: D. 72 km/h

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Q5. A sum of money doubles itself in 10 years at simple interest. In how many years will it triple?
A. 20
B. 25
C. 30
D. 15
✅ Answer: C. 30

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Q6. If 3x – 5 = 16, then x = ?
A. 5
B. 6
C. 7
D. 8
✅ Answer: C. 7

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Q7. The value of √(144) + √(121) is:
A. 22
B. 23
C. 24
D. 25
✅ Answer: D. 25

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Q8. If the perimeter of a rectangle is 60 cm and its length is 17 cm, what is its breadth?
A. 13 cm
B. 11 cm
C. 10 cm
D. 8 cm
✅ Answer: B. 13 cm

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Q9. Find the compound interest on ₹5000 at 10% per annum for 2 years.
A. ₹1050
B. ₹1100
C. ₹1155
D. ₹1200
✅ Answer: C. ₹1155

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Q10. The ratio of the ages of A and B is 3:4. After 5 years, the ratio becomes 4:5. What is A's present age?
A. 15
B. 18
C. 20
D. 21
✅ Answer: C. 20