A train , 240 m long crosses a man, walking along the line in opposite direction at the rate of 3 km/hr in 10 seconds. What is the speed of train ?
80 km/hr
75 km/hr
83.4 km/hr
92.8 km/hr
68 km/hr
Option C Let speed of train = x m/hr 240/(3 + x) 5/18 = 10 x = 83.4 km/hr
A boat takes a total of 24 hours to over 90 km in downstream and 90 km in upstream. If the ratio of speed of boat in sill water and speed of stream is 4 : 1, then find how much time is required to cover 120 km distance in down stream speed ?
8 hours
14 hours
20 hours
15 hours
12 hours
Option E Let speed of boat in still water = 4x speed of stream = x downstream speed = 4x + x = 5x upstream speed = 4x – x = 3x 90/5x + 90/3x = 24 x = 2 downstream speed = 5 * 2 = 10 km/hr time = 120/10 = 12 hours
A equilateral tringle and a square have the same area. If the perimeter of the square is 88cm, then find what is area of the equilateral tringle ?
196 cm^2
256 cm^2
144 cm^2
484 m^2
125 cm^2
Option D Perimeter of square = 88cm side of square = 88/4 = 22cm area of square = 22 * 22 = 484 cm^2 area of tringle = 484 cm^2
Pipe A can fill a tank in 15 hours and pipe B can fill the same tank in 60 hours, pipe C can empty in 10 hours. Pipe A and B are kept opened for 10 hours in the beginning and then pipe C is also opened, what is the time taken to empty the tank ?
60 hours
40 hours
30 hours
25 hours
50 hours
Option E Capacity of the tank = 15, 60, 10 = 60 units efficiency of pipe A = 60/15 = 4 units efficiency of pipe B = 60/60 = 1 efficiency of pipe C = 60/10 = 6 units tank filled in 1st 10 hours = (4 + 1) * 10 = 50 units now, when all the pipe work together, 1 unit of water will out in every minute from tank. 50 units of water will be in 50 hours.
The ratio of age of A and B, 6 years ago was 3 : 4. Sum of the present age of B and C is 80 years. C is 12 years elder to A. Find the difference of age of B and C after 4 years ?
5 years
6 years
8 years
4 years
12 years
Option D 6 years ago age of A = 3x age of B = 4x present age of A = 3x + 6 present age of B = 4x + 6 present age of C = 3x + 6 + 12 = 3x + 18 4x + 6 + 3x + 18 = 80 7x = 56 x = 8 age of B after 4 years = 4x + 6 + 4 = 42 years age of C after 4 years = 3x + 18 + 4 = 46 years difference = 46 – 42 = 4 years
Directions : What will be wrong number in the following wrong number series ? 120, 83, 113, 93, 105, 99, 101
113
83
105
120
99
Option D The series is, (- 6 * 7), (+ 5 * 6), ( – 4 * 5), ( + 3 * 4), ( – 2 * 3), ( + 1 * 2)
1898, 1870, 1657, 1608, 1096, 1015, 15
1096
1015
1898
15
1870
Option E The series is ( – 5^2 ), (- 6^3), (- 7^2), (- 8^3 ), (- 9^2), (- 10^3)
48, 84, 156, 300, 590, 1164
48
156
300
590
1164
Option D The series is, ( * 2 – 12), ( * 2 – 12)…
2, 6, 12, 24, 30, 42, 56
24
12
30
42
2
Option A The series is , (1^2 + 1), (2^2 + 2), (3^2 + 3)…
1, 6, 24, 60, 120, 210
6
1
60
24
210
Option B The series is, (1^3 – 1), (2^3 – 2), (3^3 – 3), (4^3 – 4)…
