396, 462, 572, 427, 671, 264
Question: 396, 462, 572, 427, 671, 264
[A].
396
427
671
264
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
In each number except 427, the middle digit is the sum of other two.
Similar Posts
The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
Question:
The ratio of the number of boys and girls in a college is 7 : 8. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?
[A].8 : 9 [B].
17 : 18 [C].
21 : 22 [D].
Cannot be determined Answer: Option C
Explanation:
Originally, let the number of boys and girls in the college be 7x and 8x respectively.
Their increased number is (120% of 7x) and (110% of 8x).
120 x 7x and 110 x 8x 100 100 42x and 44x 5 5 The required ratio = 42x : 44x = 21 : 22. 5 5 A train travelling at 48 kmph completely crosses another train having half its length and travelling in opposite direction at 42 kmph, in 12 seconds. It also passes a railway platform in 45 seconds. The length of the platform is
Question: A train travelling at 48 kmph completely crosses another train having half its length and travelling in opposite direction at 42 kmph, in 12 seconds. It also passes a railway platform in 45 seconds. The length of the platform is
[A].400 m [B].
450 m [C].
560 m [D].
600 m Answer: Option A
Explanation:
Let the length of the first train be x metres.
Then, the length of the second train is x metres. 2 Relative speed = (48 + 42) kmph = 90 x 5 m/sec = 25 m/sec. 18 [x + (x/2)] = 12 or 3x = 300 or x = 200. 25 2 Length of first train = 200 m.
Let the length of platform be y metres.
Speed of the first train = 48 x 5 m/sec = 40 m/sec. 18 3 (200 + y) x 3 = 45 40 600 + 3y = 1800
y = 400 m.
The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is:
Question: The difference between a positive proper fraction and its reciprocal is 9/20. The fraction is:
[A].3 5 [B].
3 10 [C].
4 5 [D].
4 3 Answer: Option C
Explanation:
Let the required fraction be x. Then 1 – x = 9 x 20 1 – x2 = 9 x 20 20 – 20×2 = 9x
20×2 + 9x – 20 = 0
20×2 + 25x – 16x – 20 = 0
5x(4x + 5) – 4(4x + 5) = 0
(4x + 5)(5x – 4) = 0
x = 4 5 The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is:
Question:
The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is:
[A].74 [B].
94 [C].
184 [D].
364 Answer: Option D
Explanation:
L.C.M. of 6, 9, 15 and 18 is 90.
Let required number be 90k + 4, which is multiple of 7.
Least value of k for which (90k + 4) is divisible by 7 is k = 4.
Required number = (90 x 4) + 4 = 364.
If A = x% of y and B = y% of x, then which of the following is true?
Question:
If A = x% of y and B = y% of x, then which of the following is true?
[A].A is smaller than B. [B].
A is greater than B [C].
Relationship between A and B cannot be determined. [D].
If x is smaller than y, then A is greater than B. Answer: Option E
Explanation:
x% of y = x x y = y x x = y% of x 100 100 A = B.
The sum of even numbers between 1 and 31 is:
Question:
The sum of even numbers between 1 and 31 is:
[A].6 [B].
28 [C].
240 [D].
512 Answer: Option C
Explanation:
Let Sn = (2 + 4 + 6 + … + 30). This is an A.P. in which a = 2, d = 2 and l = 30
Let the number of terms be n. Then,
a + (n – 1)d = 30
2 + (n – 1) x 2 = 30
n = 15.
Sn = n (a + l) = 15 x (2 + 30) = (15 x 16) = 240. 2 2