Algebra (Railway Maths) (Part – VII)

Total Questions: 50

41. If x × y = x + y + √(xy), then the value of 6 × 24 will be: [RRB NTPC 08/02/2021 (Evening)]

Correct Answer: (c) 42
Solution:

42. The roots of the equation x² − 7x + 12 = 0 are: [RRB NTPC 08/02/2021 (Evening)]

Correct Answer: (a) 3, 4
Solution:

43. Solve the following: (1/5 x − 1/6 y)(5x + 6y) = ? [RRB NTPC 09/02/2021 (Morning)]

Correct Answer: (a) x² + 11xy/30 − y²
Solution:

44. If a + b + c = 8 and both b and c are positive integers greater than zero, then the maximum value ‘a’ can take is: [RRB NTPC 09/02/2021 (Evening) ]

Correct Answer: (a) 6
Solution:

a + b + c = 8
b and c are greater than 0. For maximum value of a take b and c is equal to 1
a = 8 - 2 = 6

45. If 1.5x = 0.04y, then what will be the value of (y - x / y + x) ? [RRB NTPC 10/02/2021 (Morning) ]

Correct Answer: (a) 73 / 77
Solution:

46. If 3a = 4b = 6c and a + b + c = 27√29, then what will be the value of √(a² + b² + c²)? [RRB NTPC 10/02/2021 (Morning)]

Correct Answer: (d) 87
Solution:

47. Select the term that can replace the question mark (?) in the following equation. (2a³ − 3)(5a³ − 2) = 10a⁶ + ? + 6 [RRB NTPC 10/02/2021 (Morning)]

Correct Answer: (b) −19a³
Solution:

48. If 144 / 0.144 = 14.4 / x, then what is the value of x? [RRB NTPC 10/02/2021 (Evening)]

Correct Answer: (c) 0.0144
Solution:

49. If x / y = 6 / 5, then the value of (x² + y²) / (x² − y²) is [RRB NTPC 11/02/2021 (Morning)]

Correct Answer: (a) 61/11
Solution:

50. If x = (√3 + 1) / (√3 − 1) and y = (√3 − 1) / (√3 + 1), then the value of x² + y² is: [RRB NTPC 11/02/2021 (Evening)]

Correct Answer: (a) 14
Solution: