A man is riding a bike with front and back wheel circumference of 40 inches and 70 inches respectively. If the man rides the bike on a straight road without slippage, how many inches will the man have travelled when the front wheel has made 15 revolutions more than the back wheel?

Correct Answer: 70 kms

Explanation:

Let the time taken by train be 't' hrs.

Then,

40 t = 35 t + 15 60

40t = 35t + 35/4

t = 7/4 hrs

Therefore, Required length of the total journey d = s x t

= 40 x 7/4

= 70 kms.

Correct Answer: 4.18

Explanation:

Distance to be covered =  ?D = 40 ? km 

Relative speed of bikers = 16 + 14 = 30 kmph.

 

Now,  t i m e = d i s tan c e s p e e d =   40 ? 30 = 4.18 hrs.

Correct Answer: 11

Explanation:

Do not assume that AB and C are on a straight line. Make a diagram with A and B marked 5 miles apart. Draw a circle centered on B, with radius 6. C could be anywhere on this circle. The minimum distance will be 1, and maximum 11

Correct Answer: 4 kms

Explanation:

Let the actual distance be t kms

Now, According to the data,

 

$$\begin{gathered} 5 t + 8 60 = 6 t \\ = > 5 60 t + 8 60 = 6 t \\ = > 60 t + 8 = 72 t \\ = > 8 = 12 t \\ = > t = 8 / 12 = 2 / 3 hrs \end{gathered}$$

 

Now, the total distance = 6t = 6 x 2/3 = 2 x 2 = 4 kms.

Correct Answer: 20 km

Explanation:

Average speed = 2 a b a + b, here a=25 b=4
= 2 x 25 x 4/(25+4) = 200/29 km/hr.

Distance covered in 5 hours 48 minutes
= Speed x time = (200/29)x (29/5) Distance covered in 5 hours 48 minutes = 40kms.

Distance of the post office from the village = (40/2) = 20 km.

Correct Answer: 48 kmph

Explanation:

Let the initial speed of Akhil be '4p' kmph

Then speed after decrease in speed = '3p' kmph

We know that, 

Change in speed == Change in time

According to the given data,

$$\begin{gathered} 24 3 p - 24 4 p = 35 - 25 60 \\ = > p = 12 \end{gathered}$$

 

Hence, the initial speed of Akhil = 4p = 4 x 12 = 48 kmph.

Correct Answer: None of these

Explanation:

Let t be the time after Kajol starts, when she meets Ajay, then 

               t = 300/(x+y) 

 This should be less than 2.5 or (x+y)>120 

Since       y= 3x/2  =>  y > 72

This (y>72) is greater than 67.5 km/h and hence Shahrukh will always overtake Ajay before he meets Kajol.

Correct Answer: 27 sec

Explanation:

Time taken to meet for the first time anywhere on the track

= length of the track / relative speed

= 300 / (15 + 25)5/18 = 300x 18 / 40 x 5 = 27 seconds.

Correct Answer: 99

Explanation:

Let, Distance between A and B = d

 

Distance travelled by P while it meets Q = d + 11

 

Distance travelled by Q while it meets P = d ? 11

 

Distance travelled by Q while it meets R = d + 9

 

Distance travelled by R while it meets Q = d ? 9

 

Here the ratio of speeds of P & Q => SP : SQ = d + 11 : d ? 11

 

The ratio of speeds of Q & R => SQ : SR = d + 9 : d ? 9

 

But given Ratio of speeds of P & R => P : R = 3 : 2

  S P S R = S P S Q x S Q S R = d + 11 d + 9 d - 11 d - 9

 

=>  d + 11 d + 9 d - 11 d - 9 = 3/2

 

=>  d = 1, 99

 

=> d = 99 satisfies.

 

Therefore, Distance between A and B = 99

Correct Answer: 17 hours

Explanation:

In this type of questions we need to get the relative speed between them,
The relative speed of the boys = 5.5kmph ? 5kmph
= 0.5 kmph

Distance between them is 8.5 km
Time = Distance/Speed
Time= 8.5km / 0.5 kmph = 17 hrs