A) 456 kms | B) 482 kms |

C) 552 kms | D) 556 kms |

Explanation:

Total distance travelled in 12 hours =(35+37+39+.....upto 12 terms)

This is an A.P with first term, a=35, number of terms,

n= 12,d=2.

Required distance = 12/2[2 x 35+{12-1) x 2]

=6(70+23)

= 552 kms.

A) 5 kmph | B) 10 kmph |

C) 15 kmph | D) 45 kmph |

Explanation:

Speed of the boat downstream =

Speed of the boat upstream

The speed of the stream = .

A) 40 km | B) 50 km |

C) 70 km | D) 80 km |

Explanation:

Let the total distance be 'x' km.

Time taken to cover remaining 40% of x distance is

But given time taken to cover first 60% of x distance is

x=80 km.

A) 6.52 | B) 8.14 |

C) 4.18 | D) 5.02 |

Explanation:

Distance to be covered = = 40 km

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

Now, = = 4.18 hrs.

A) 1100 | B) 1300 |

C) 1400 | D) 1200 |

Explanation:

Given the ratio of the circumference of front wheel is 40 inches and back wheel is 70 inches

Distance covered = Circumference of the wheel × No. of Revolutions made by the wheel

If n is the number of revolutions made by back wheel, the number of revolutions made by front wheel is n+15

Distance covered by both the wheels is the same

40*(n+3)=70n

n=20

Front wheel : Back Wheel

Circumference 40 : 70

Revolutions 35 : 20

Distance covered 40×35 = 70×20 = 1400 inches.

A) 22 sec | B) 32 sec |

C) 42 sec | D) 52 sec |

Explanation:

Given that,

1st train speed = 62 km/hr

2nd train speed = 44 km/hr

Hence the relative speed of two trains is 62-44 = 18 km/hr m/s = 5 m/s.

There fore, the first train crosses the second train i.e (85+75)mts of distance with a speed of 5m/s in,

time** = ** = 32 sec.