Quiz Discussion

One third of a certain journey is covered at the rate of 25 km/hr, one forth at the rate of 30 km/hr and the rest at 50 km/hr. The average speed for the whole journey is :

• 1]

  35 km/hr

• 2]

  \(33\frac{1}{3}\) km/hr

• 3]

  30 km/hr

• 4]

  \(37\frac{1}{12}\) km/hr

A man covers half of his journey at 6 km/h and the remaining half at 3 km/h. His average speed is

• 1] 9 km/h
• 2] 4.5 km/h
• 3] 4 km/h
• 4] 3 km/h

Points 'A' and 'B' are 70 km apart on a highway and two cars start at the same time. If they travel in the same direction, they meet in 7 hours, but if they travel towards each other they meet in one hour. Find the speed of the two cars (in km/hr).

• 1] 20, 30
• 2] 40, 30
• 3] 30, 50
• 4] 20, 40

With an uniform speed, a car covers a distance in 8 hours. had the speed been increased by 4 km/hr, the same distance could have been covered in 7 hr and 30 min. What is the distance covered ?

• 1] 420 km
• 2] 480 km
• 3] 520 km
• 4] 640 km

A ship leaves on a long voyage. When it is 18 miles from shore, a sea plane, whose speed is ten times that of the ship, is sent to deliver mail. How far from the shore does the sea plane catch up with the ship?

• 1] 24 miles
• 2] 25 miles
• 3] 22 miles
• 4] 20 miles
• 5] None of these

Two cars start simultaneously from cities A and B, towards B and A respectively, on the same route. Once the two cars reach their destinations they turned around and move towards the other city without any loss of time. The two cars continue shuttling in this manner for exactly 20 hours. If the speed of the car starting from A is 60km/hr and the speed of the car starting from B is 40km/hr and the distance between the two cities is 120 km, find the number of times the two cars cross each other?

• 1] 8
• 2] 10
• 3] 12
• 4] 20
• 5] Can't be determined

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

The length of a train and that of a platform are equal. If with a speed of 90 km/hr the train crosses the platform in one minute, then the length of the train (in meters) is ?

• 1] 500 meters
• 2] 600 meters
• 3] 750 meters
• 4] 900 meters

How long must a driver take to drive the final 70 miles of a trip if he wants to average 50 miles an hour for the entire trip and during the first part of the trip he drove 50 miles in \(1\frac{1}{2}\) hours ?

• 1] 54 min
• 2] 1 hr
• 3] 66 min
• 4] 70 min

The average speed of a bus is one-third of the speed of a train. The train covers 1125 km in 15 hours. How much distance will the bus cover in 36 minutes ?

• 1] 12 km
• 2] 18 km
• 3] 21 km
• 4] 75 km
• 5] None of these