Simplification (Railway Maths) (801 to 819)

Total Questions: 19

11. Which of the fractions given below, when added to 5/7 gives 1? [RRB ALP 30/08/2018 (Afternoon) ]

Correct Answer: (c) 6/21
Solution:

Required fraction = 1 - 5/7
= 7 - 5/7 = 2/7 or 6/21

12. 18% of 60 is 54% of ______ . [RRB ALP 30/08/2018 (Afternoon)]

Correct Answer: (a) 20
Solution:

Let the required no be x
ATQ,
18% of 60 = 54% of x
1080 = 54x ⇒ x = 1080/54 = 20

13. Which of the numbers given below is the square root of 16384 ? [RRB ALP 30/08/2018 (Evening)]

Correct Answer: (a) 128
Solution:

Square root of 16384
= √16384 = √256 × 64 = 16 × 8 = 128

14. Which of the below given fractions is not equal to 9/17 ? [RRB ALP 31/08/2018 (Morning)]

Correct Answer: (a) 108/221
Solution:

15. Select the option that can replace the question mark (?) in the following equation. [RRB ALP 31/08/2018 (Morning)]

(0.2)³ − (0.1)³ / (0.2 + 0.1)² = ?

Correct Answer: (b) 7/90
Solution:

16. Select the option that can replace the question mark (?) in the following equation. [RRB ALP 31/08/2018 (Afternoon)]

(0.3)³ + (0.2)³ / (0.3 − 0.2)² = ?

Correct Answer: (b) 7/2
Solution:

17. What is the value of |3(1) − 6|? [RRB ALP 31/08/2018 (Evening)]

Correct Answer: (d) 3
Solution:

|3(1) - 6|
= |3 - 6| = |- 3| = 3

18. Evaluate : [RRB ALP 31/08/2018 (Evening) ]

Correct Answer: (d) 10
Solution:

19. (5x − 3)(x + 4) − (2x + 5)(3x − 4) = ? [RRB ALP 31/08/2018 (Evening)]

Correct Answer: (d) −x² + 10x + 8
Solution:

(5x - 3) (x + 4) - (2x + 5)(3x - 4)
= (5x 2 + 20x - 3x - 12) - (6x 2 - 8x + 15x - 20)
= 5x 2 + 20x - 3x - 12 - 6x 2 + 8x - 15x + 20
= -x 2 + 10x + 8