A) 600 | B) 750 |

C) 1000 | D) 1250 |

Explanation:

speed = (5x5/18)m/sec

= 25/18 m/sec.

Distance covered in 15 minutes = (25/18 x 15 x 60)m

= 1250 m.

A) 4 mile/hr | B) 6 mile/hr |

C) 2 mile/hr | D) 5 mile/hr |

Explanation:

Let the speed of river and boat be 'r' m/min and 'b' m/min.

so relative speed in upstream (b-r)m/min and in downstream (b+r)m/min.

Now in upstream distnce covered in 5 min is 5(b-r)miles

so total distnce covered => 1 + 5(b-r)miles in upstream

In downstream distance covered in 5min is 5(b+r)miles

Now 1 + 5(b-r) = 5(b+r)

1+5b-5r = 5b+5r

1 = 10r

r = 1/10 mile/min => 6 mile/hr.

A) 9 m/h | B) 3 m/h |

C) 6 m/h | D) 12 m/h |

Explanation:

let, speed of Ali=X mph and Faizer=Y mph

Now, relative speed when Ali is walking int the same direction with Faizer= (X-Y)mph

hence, according to question, 27/(X-Y)=9 ; solving X-Y=3; --- (1)

Now relative speed when walking in the opposite direction= (X+Y) mph

hence, according to question, 27/(X+y)=3; solving X+Y=9; --- (2)

solving 1 and 2 we get X=6 and Y=3, where X is the speed of Ali.

A) 9 and 3 kmph | B) 6 and 7 kmph |

C) 8 and 1 kmph | D) 7 and 2 kmph |

Explanation:

Downstream speed = 72km/8hrs = 9 kmph

upstream speed = 84km/12hrs = 7 kmph

speed of boat = avg of downstream and upstream speeds

speed of boat = (9+7)/2kmph = 8 kmph.

current speed = half of the difference of downstream and upstream speeds

currend speed = (9-7)/2kmph = 1 kmph

A) 900 mts | B) 300 mts |

C) 250 mts | D) 500 mts |

Explanation:

Using pythagarous theorem,

distance travelled by first train = 36x5/18x30 = 300m

distance travelled by second train = 48x5/18x30 = 400m

so distance between them =√( 90000 + 160000) = √250000 = 500mts.

A) 55 kms | B) 35 kms |

C) 25 kms | D) 65 kms |

Explanation:

Let x and y be the respective km's travelled by man via taxi and by his own car.

Given x + y = 90 => x = 90 - y

But according to the question,

7x + 6y = 595

7(90-y) + 6y = 595

=> 630 - 7y + 6y = 595

=> y = 630 - 595 = 35

=> x = 90 - 35 = 55

Therefore, the distance travelled by taxi is 55 kms.