Algebra (Railway Maths) (Part – VII)

Total Questions: 50

1. If x² + 1 = 2x, then find x − (1/x) [RRB NTPC 16/01/2021 (Evening)]

Correct Answer: (a) 0
Solution:

2. If the equation x² + ax + b = 0 and x² + bx + a = 0 have a common root, then find the value of a + b (where a is not equal to b). [RRB NTPC 18/01/2021 (Morning)]

Correct Answer: (d) −1
Solution:

3. If x = √3 + √2, then the value of x² + 1/x² is: [RRB NTPC 19/01/2021 (Evening)]

Correct Answer: (d) 10
Solution:

4. The value of 4x⁴ + 9y² − 12x²y at x = 5 and y = 2 is [RRB NTPC 19/01/2021 (Evening)]

Correct Answer: (a) 1936
Solution:

5. The value of 16x⁴ + 25y² − 40x²y at x = 5 and y = 2 is [RRB NTPC 20/01/2021 (Morning)]

Correct Answer: (b) 8100
Solution:

6. In the expression (x + 3)³, the coefficient of x is [RRB NTPC 20/01/2021 (Evening)]

Correct Answer: (d) 27
Solution:

7. What is the value of x, if −3 × √196 + √x = 8 × 3 − 2 [RRB NTPC 21/01/2021 (Morning)]

Correct Answer: (a) 4096
Solution:

8. If (√5 + √2) / (√5 − √2) = a + b√10, then which of the following is correct? [RRB NTPC 22/01/2021 (Evening)]

Correct Answer: (d) a = 7/3, b = 2/3
Solution:

9. The sum of two numbers is 75 and the difference of their squares is 300. Find the difference between the two numbers. [RRB NTPC 23/01/2021 (Morning) ]

Correct Answer: (a) 4
Solution:

10. If x/5 = y/6 = z/11, then x + y + z / z is equal to: [RRB NTPC 23/01/2021 (Morning) ]

Correct Answer: (c) 2
Solution: