Quiz Discussion

A car takes 15 minutes less to cover a distance of 75 km, if it increases its speed by 10 km/hr from its usual speed. How much time would it take to cover a distance of 300 km using this speed ?

• 1]

  5 hrs

• 2]

  \(5\frac{1}{2}\) hrs

• 3]

  6 hrs

• 4]

  \(6\frac{1}{2}\) hrs

A salesman travels a distance of 50 km in 2 hours and 30 minutes. How much faster, in kilometres per hour, n a n average must he travel to make such a trip in 5656 hour less time?

• 1]

  10

• 2]

  20

• 3]

  30

• 4]

  None Of these

An ant moved for several seconds and covered 3 mm in the first second and 4 mm more in each successive second than its predecessor. If the ant had covered 1 mm in the first second and 8 mm more in each successive second, then the difference between the path it would cover during the same time and actual path would be more than 6 mm but less than 30 mm. find the time for which the ant moved (in seconds).

• 1] 5 s
• 2] 4 s
• 3] 6 s
• 4] 2 s
• 5] None of these

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

A train met with an accident 120 km from station A. It completed the remaining journey at \(\frac{5}{6}\) of its previous speed and reached 2 hours late at station B. Had the accident taken place 300 km further, it would have been only 1 hour late. What is the speed of the train?

• 1] 100 km/h
• 2] 12 km/h
• 3] 60 km/h
• 4] 50 km/h

A star is 8.1 × 1013 km away from the earth. Suppose light travels at the speed of 3.0 × 105 km per second. How long will it take the light from the star to reach the earth ?

• 1] 7.5 × 103 hours
• 2] 7.5 × 104 hours
• 3] 2.7 × 1010 seconds
• 4] 2.7 × 1011 seconds

A train approaches a tunnel AB. Inside the tunnel, a cat is located at a point i.e. \(\frac{5}{{12}}\) of the distance AB measured from entrance A. When the train whistles the Cat runs. If the cat moves to exit B, the train catches the cat exactly at the exit. The speed of the train is greater than the speed of the cat by what order?

• 1] 1 : 6
• 2] 3 : 5
• 3] 6 : 1
• 4] 5 : 4
• 5] None of these

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

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

The speed of 90 km per hour is same as :

• 1] 9 m/s
• 2] 20 m/s
• 3] 25 m/s
• 4] 28 m/s

Two cyclists start from the same place in opposite directions. One goes towards north at 18 kmph and the other goes towards south at 20 kmph. What time will they take to be 47.5 km apart ?

• 1]

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

• 2]

  \({ \text{2}}\frac{1}{4}{ \text{ hrs}}\)

• 3]

  2 hrs 23 min

• 4]

  \({ \text{2}}\frac{1}{2}{ \text{ hrs}}\)