Quiz Discussion

A person can row a boat d km upstream and the same distance downstream in 5 hours 15 minutes. Also, he can row the boat 2d km upstream in 7 hours. How long will it take to row the same distance 2d km downstream?

• 1]

  \(\frac{{3}}{{2}}\) hours

• 2]

  7 hours

• 3]

  \(\frac{{29}}{{4}}\) hours

• 4]

  \(\frac{{7}}{{2}}\) hours

Ravi walks to and fro to a shopping mall. He spends 30 minutes shopping. If he walks at a speed of 10 km an hour, he returns home at 19.00 hours. If he walks at 15 km an hour, her returns home at 18.30 hours. How far must he walk in order to return home at 18.15 hours ?

• 1] 17 km/hr
• 2] 17.5 km/hr
• 3] 18 km/hr
• 4] 19 km/hr
• 5] None of these

A person travels three equal distance at a speed of x km/hr, y km/hr and z km/hr respectively. What is the average speed for the whole journey ?

• 1]

  \(\frac{{xyz}}{{3\left( {xy + yz + zx} \right)}}\)    km/hr

• 2]

  \(\frac{{xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

• 3]

  \(\frac{{\left( {xy + yz + zx} \right)}}{{xyz}}\)    km/hr

• 4]

  \(\frac{{3xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

Two boats, travelling at 5 km/h and 10 km/h, head directly towards each other. They begin at a distance of 20 km from each other. How far apart are they (in km) one minute before they collide?

• 1]

  \(\frac{{1}}{{12}}\)

• 2]

  \(\frac{{1}}{{6}}\)

• 3]

  \(\frac{{1}}{{4}}\)

• 4]

  \(\frac{{1}}{{3}}\)

• 5]

  None of these

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

If Karan travels at a speed of 60 kmph and covers a distance in 9 hrs., then how much time will he take to travel the same distance at a speed of 90 kmph ?

• 1] 8 hours
• 2] 6 hours
• 3] 12 hours
• 4] 9 hours

Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour ?

• 1] 9 min
• 2] 10 min
• 3] 12 min
• 4] 20 min

A tiger is 50 of its own leaps behinds a deer. The tiger takes 5 leaps and per minutes to the deer's 4. If the tiger and the deer cover 8 m and 5 m per leap respectively, what distance will the tiger have to run before it caches the deer?

• 1] 600 m
• 2] 700 m
• 3] 800 m
• 4] 1000 m
• 5] None of these

A car after traveling 18 km from a point A developed some problem in the engine and the speed became \(\frac{4}{5}\) th of its original speed. As a result, the car reached point B 45 minutes late. If the engine had developed the same problem after traveling 30 km from A, then it would have reached 36 minutes late. The original speed of the car (in km/h) is:

• 1] 25 kmph
• 2] 30 kmph
• 3] 20 kmph
• 4] 35 kmph
• 5] None of these

A person can row \(7\frac{1}{2}\) km an hour in still water. Finds that it takes twice the time to row upstream than the time to row downstream. The speed of the stream is:

• 1] 2 kmph
• 2] 2.5 kmph
• 3] 3 kmph
• 4] 4 kmph