Quiz Discussion

A candle of 6 cm long burns at the rate of 5 cm in 5 hour and an another candle 8 cm long burns at the rate of 6 cm in 4h. What is the time required to each candle to remain of equal lengths after burning for some hours, when they starts to burn simultaneously with uniform rate of burning?

• 1] 1 hours
• 2] 1.5 hours
• 3] 2 hours
• 4] 3 hours
• 5] 4 hours

The diameter of each wheel of car is 70 cm. If each wheel rotates 400 times per minutes, then the speed of the car (in km/hr) if : \(\left( {{ \text{Take }}pi = \frac{{22}}{7}} \right)\)

• 1] 5.28 km/hr
• 2] 528 km/hr
• 3] 52.8 km/hr
• 4] 0.528 km/hr

A motorboat in still water travels at speed of 36 kmph. It goes 56 km upstream in 1 hour 45 minutes. The time taken by it to cover the same distance down the stream will be:

• 1] 2 Hours 25 Minutes
• 2] 3 Hours
• 3] 1 Hours 24 Minutes
• 4] 2 Hours 21 Minutes

Train X leaves New York at 1 am and travels east at a constant speed of x mph. If train Z leaves New York at 2 am and travels east, at what constant rate of speed will train Z have to travel in order to catch train X at exactly 5.30 am ?

• 1]

  \(\frac{5}{6}x\)

• 2]

  \(\frac{9}{8}x\)

• 3]

  \(\frac{6}{5}x\)

• 4]

  \(\frac{9}{7}x\)

• 5]

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

A dog start chasing to a cat 2 hour later. It takes 2 hours to dog to catch the cat. If the speed of the dog is 30 km/h. what is the speed of cat?

• 1] 10 km/h
• 2] 12 km/h
• 3] 15 km/h
• 4] 20 km/h

A thief steals a car at 2.30 pm and drives it at 60 kmph. The theft is discovered at 3 pm and the owner sets off in another car at 75 kmph. When will he overtake the thief ?

• 1]

  4.30 pm

• 2]

  4.45 pm

• 3]

  5 pm

• 4]

   5.15 pm

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

Two boys A and B start at the same time to ride from Delhi to Meerut, 60 km away. A travels 4 km an hours slower than B, B reaches Meerut and at once turns back meeting A, 12 km from Meerut. A's rate was :

• 1] 4 km/hr
• 2] 8 km/hr
• 3] 12 km/hr
• 4] 16 km/hr

A thief is noticed by a policeman from a distance of 200 metres the thief starts running and the policeman chases him. The thief and the policeman run at the rate of 10 km/hr and 11 km/hr respectively. What is the distance between them after 6 minutes ?

• 1] 100 m
• 2] 190 m
• 3] 200 m
• 4] 150 m

A cyclist drove one kilometre, with the wind in his back, in 3 minutes and drove the same way back, against the wind, in 4 minutes. If we assume that the cyclist always puts constant force on the pedals, how much time would it take him to drive 1 km without wind ?

• 1]

  \(2\frac{1}{3}\) min

• 2]

  \(2\frac{3}{7}\) min

• 3]

  \(3\frac{3}{7}\) min

• 4]

  \(3\frac{7}{12}\) min