Q:

A) 45 | B) 50 |

C) 55 | D) 60 |

Answer: B) 50

Explanation:

Explanation:

let speed of boat= X, speed of stream= Y

Upstream speed= X-Y

Downstream speed= X+Y

Sum of upstream & downstream= (X-Y) +(X+Y)= 2X

So, 2X= 40

X= 20 km/hr

Speed of boat : speed of stream= 600+100 :100= 7:1

So speed of Stream= 20/7 km/hr

ATQ, D/( X-Y) + D/( X+Y) = 5

D/(120/7) + D/(160/7)= 5

D= 480×5/49= 48.97 km= 50 Km(approx)

3
722

4
664

1
519

4
701

0
655

1
1719

Q:

A) 2(2 + √17) | B) 3(2 + √17) |

C) 2(4 + √15) | D) 3(4 + √17) |

3
1375

Q:

A) 0.20 Hz | B) 625 Hz |

C) 250 Hz | D) 100 Hz |

2
1328