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80. A train 800 metres long is running at a speed of 78 km/hr. If it crosses a tunnel in 1 minute, then the length of the tunnel (in meters) is:

[A]. 130

[B]. 360

[C]. 500

[D]. 540

✅ The correct answer is option C.
Speed =

78 x
5

m/sec
=

m/sec.

18
3

Time = 1 minute = 60 seconds.
Let the length of the tunnel be x metres.

Then,

800 + x

=
65

60
3

3(800 + x) = 3900
x = 500.

82. Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is:

[A]. 50 m

[B]. 72 m

[C]. 80 m

[D]. 82 m

✅ The correct answer is option A.
Let the length of each train be x metres.
Then, distance covered = 2x metres.
Relative speed = (46 – 36) km/hr

10 x
5
m/sec

25
m/sec

2x
=
25

36
9

2x = 100
x = 50.

84. How many seconds will a 500 metre long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr?

[A]. 25

[B]. 30

[C]. 40

[D]. 45

✅ The correct answer is option B.
Speed of the train relative to man
= (63 – 3) km/hr

= 60 km/hr

60 x
5

m/sec

m/sec.

Time taken to pass the man

500 x
3

sec

= 30 sec.

60. Find out the wrong number in the given sequence of numbers.: 22, 33, 66, 99, 121, 279, 594

[A]. 33

[B]. 121

[C]. 279

[D]. 594

✅ The correct answer is option C.
Each of the number except 279 is a multiple of 11.

47. Insert the missing number.: 15, 31, 63, 127, 255, (….)

[A]. 513

[B]. 511

[C]. 517

[D]. 523

✅ The correct answer is option B.
Each number is double the preceding one plus 1.
So, the next number is (255 x 2) + 1 = 511.

48. Find out the wrong number in the given sequence of numbers.: 125, 127, 130, 135, 142, 153, 165

[A]. 130

[B]. 142

[C]. 153

[D]. 165

✅ The correct answer is option D.
Prime numbers 2, 3, 5, 7, 11, 13 are to be added successively.
So, 165 is wrong.

49. Find the odd man out.: 10, 25, 45, 54, 60, 75, 80

[A]. 10

[B]. 45

[C]. 54

[D]. 75

✅ The correct answer is option C.
Each of the numbers except 54 is multiple of 5.

50. Insert the missing number.: 4, -8, 16, -32, 64, (….)

[A]. 128

[B]. -128

[C]. 192

[D]. -192

✅ The correct answer is option B.
Each number is the proceeding number multiplied by -2.
So, the required number is -128.

51. Find out the wrong number in the series.: 3, 7, 15, 27, 63, 127, 255

[A]. 7

[B]. 15

[C]. 27

[D]. 63

✅ The correct answer is option C.
Go on multiplying the number by 2 and adding 1 to it to get the next number.
So, 27 is wrong.

52. Insert the missing number.: 10, 5, 13, 10, 16, 20, 19, (….)

[A]. 22

[B]. 40

[C]. 38

[D]. 23

✅ The correct answer is option B.
There are two series (10, 13, 16, 19) and (5, 10, 20, 40), one increasing by 3 and the other multiplied by 2.

Author name: Admin