Quiz Discussion

Two planes move along a circle of circumference 1.2 kms with constant speeds. When they move in different directions, they meet every 15 seconds and when they move in the same direction one plane overtakes the other every 60 seconds. The speed of the slower plane is :

• 1] 0.02 km/sec
• 2] 0.03 km/sec
• 3] 0.04 km/sec
• 4] 0.05 km/sec

A train 300 m long is running with a speed of 54 km/hr. In what time it cross a telephone pole ?

• 1] 20 seconds
• 2] 15 seconds
• 3] 17 seconds
• 4] 18 seconds

A man can cross a downstream river by steamer in 40 minutes and same by boat in 1 hour. If the time of crossing Upstream by streamer is 50% more than downstream time by steamer and the time required by boat to cross same river by boat in upstream is 50% more than time required by in downstream. What is the time taken for the man to cross the river downstream by steamer and then return to same place by boat half the way and by steamer the rest of the way?

• 1] 85 minutes
• 2] 115 minutes
• 3] 120 minutes
• 4] 125 minutes
• 5] None of these

Mr A started half an hour later than usual for the marketplace. But by increasing his speed to \(\frac{3}{2} \)times his usual speed he reached 10 minutes earlier than usual. What is his usual time for this journey?

• 1] 1 hours
• 2] 2 hours
• 3] 3 hours
• 4] 45 minutes
• 5] None of these

Roorkee express normally reaches its destination at 50 km/h in 30 hours. Find the speed at which it travels to reduce the time by 10 hours?

• 1] 38 km/h
• 2] 76 km/h
• 3] 75 km/h
• 4] 60 km/h

A walk at a uniform rate of 4 km an hour; and 4 hr after his start, B bicycles after him at the uniform rate of 10 km an hour. How far from the starting point will B catch A ?

• 1] 16.7 km
• 2] 18.6 km
• 3] 21.5 km
• 4] 26.7 km

Two runner start running together for a certain distance, one at 5 km/h and another at 8 km/h. The former arrives one and half an hour before the latter. The distance in Km is :

• 1] 12 km
• 2] 20 km
• 3] 25 km
• 4] 36 km

In a race of 200 meters, B can gives a start of 10 meters to A, and C can gives a start of 20 meters to B. The starts that C can gives to A, in the same race is:

• 1] 30 meters
• 2] 25 meters
• 3] 29 meters
• 4] 27 meters

A train passes two bridges of length 500 metres and 250 metres in 100 seconds and 60 seconds respectively. The length of the train is :

• 1] 125 metres
• 2] 250 metres
• 3] 120 metres
• 4] 152 metres

Two trains started at the same time, one from A to B and other from B to A. if they arrived at B and A respectively in 4 hours and 9 hours after they passed each other, the ratio of the speeds of the two trains was:

• 1] 2 : 1
• 2] 3 : 2
• 3] 4 : 3
• 4] 5 : 4