Q:

A) 7:4 | B) 11:4 |

C) 4:7 | D) 8:3 |

Answer: D) 8:3

Explanation:

Explanation:

Let the speed of the boat upstream be p kmph and that of downstream be q kmph

Time for upstream = 8 hrs 48 min = $8\frac{4}{5}$hrs

Time for downstream = 4 hrs

Distance in both the cases is same.

=> p x $8\frac{4}{5}$= q x 4

=> 44p/5 = 4q

=> q = 11p/5

Now, the required ratio of Speed of boat : Speed of water current

= $\frac{\mathbf{q}\mathbf{+}\mathbf{p}}{\mathbf{2}}\mathbf{:}\frac{\mathbf{q}\mathbf{-}\mathbf{p}}{\mathbf{2}}$

=> (11p/5 + p)/2 : (11p/5 - p)/2

=> 8 : 3

2
260

1
309

1
232

2
280

0
413

1
1410

Q:

A) 2(2 + √17) | B) 3(2 + √17) |

C) 2(4 + √15) | D) 3(4 + √17) |

3
1068

Q:

A) 0.20 Hz | B) 625 Hz |

C) 250 Hz | D) 100 Hz |

2
1097