Q:

A) 4 hrs 10 min | B) 3 hrs 15 min |

C) 3 hrs 30 min | D) 4 hrs 1 min |

Answer: C) 3 hrs 30 min

Explanation:

Explanation:

Let the speed of boat and stream be x and y kmph respectively.

According to question

d/x+y + d/x-y = 5h 15m or 21/4 hrs ......(i)

and 2d/x-y = 7...... (ii)

From eq. (i) and (ii)

2d/x+y = 7/2

Hence, Amith will take to row 2d km distance downstream in 7/2 hrs

= 3.5 hrs

= 3 hrs 30 min.

Q:

A) 2(2 + √17) | B) 3(2 + √17) |

C) 2(4 + √15) | D) 3(4 + √17) |

0
795

Q:

A) 0.20 Hz | B) 625 Hz |

C) 250 Hz | D) 100 Hz |

1
890

1
896

0
1096

Q:

A) 4 kmph | B) 2 kmph |

C) 3 kmph | D) 1 kmph |

1
1115

4
1704

1
1437

Q:

A) 75 kmph | B) 70 kmph |

C) 60 kmph | D) 65 kmph |

3
1765