A) 4.58 kms | B) 6.35 kms |

C) 5.76 kms | D) 5.24 kms |

Explanation:

Speed in still water = 6 kmph

Stream speed = 1.2 kmph

Down stream = 7.2 kmph

Up Stream = 4.8 kmph

x/7.2 + x/4.8 = 1

x = 2.88

Total Distance = 2.88 x 2 = 5.76 kms

A) 8 m/h | B) 5 m/h |

C) 7 m/h | D) 6 m/h |

Explanation:

As the distance travelled is constant, the time taken is inversely proportional to speed.

Let **'u'** be the speed of the current and **'v'** be the speed of the boat.

Speed of the boat downstream = **v + u** & upstream = **v - u**

=> v+u/v-u = 30/20 => v/u = 5 => v = 5u

=> v + u = 6u = 10/20/60 miles/hr

=> 6u = 30 m/h

=> u = **5 m/h**

A) 14 kmph | B) 13 kmph |

C) 12 kmph | D) 11 kmph |

Explanation:

The distance is constant in this case.

Let the time taken for travel with a speed of 10 kmph be '**t**'.

Now the speed of 15 kmph is **3/2** times the speed of 10 kmph.

Therefore, time taken with the speed of 15 kmph will be 2t/3 (**speed is inversely proportional to time**)

Extra time taken = t - 2t/3 = t/3

=> 1pm - 11am = 2hrs

=> t/3 = 2h

=> t = 6 hrs.

Now, Distance = **speed x time** = 10 x 6 = 60 kms

Time he takes to reach at noon = 6 - 1 = 5 hrs

Now, Speed = 60/5 = **12 kmph.**

A) 1 kmph | B) 3 kmph |

C) 5 kmph | D) 4 kmph |

Explanation:

Let the speed of the stream = x kmph

From the given data,

=> x = 3 kmph

Therefore, the speed of the stream = **3 kmph**

A) 222 m 44 cm | B) 204 m |

C) 201 m 21 cm | D) 208 m |

Explanation:

To find the minimum distance, we have to get the LCM of 75, 80, 85

Now, LCM of 75, 80, 85 = 5 x 15 x 16 x 17 = **20400**

Hence, the minimum distance each should walk so that thay can cover the distance in complete steps = 20400 cms = 20400/100 = **204 mts.**

A) 60 | B) 120 |

C) 360 | D) 6 |

Explanation:

For this we have to find the LCM of 24, 36 and 30

LCM of 24, 36 and 30 = 360 sec

360/60 min = 6 minutes.