A) 28 km/h | B) 30 km/h |

C) 40 km/h | D) 20 km/h |

Explanation:

Let the normal speed be x km/h, then

$\frac{80}{x}-\frac{80}{(x+4)}=1$

$\Rightarrow $${x}^{2}+4x-320=0$

$\Rightarrow $x (x + 20) - 16 (x + 20) = 0

(x + 20 ) (x - 16) =0

x = 16 km/h

Therefore (x + 4) = 20 km/h

Therefore increased speed = 20 km/h

A) 19 km | B) 15 km |

C) 12 km | D) 20 km |

Explanation:

Let total distance be **2D**.

He walks half distance i.e, (2D/2) = 'D' distance with **3 kmph** and

The next 'D' with** 6 kmph.**

Using formula,

**Time = Distance/speed**

(D/3) + (D/6) = 5

D =10 ,

Hence,** Total distance 2D = 20 kms.**

A) 60 kmph | B) 90 kmph |

C) 100 kmph | D) 120 kmph |

A) 24 | B) 28 |

C) 32 | D) 30 |

Explanation:

Difference in time taken = 4min = **1/15 hr**

Let the total distance covered by person be **D km**.

Then,

⇒ **D/40 – D/45 = 1/15**

⇒ 5D = 120

⇒ D = 24 km

∴ Distance covered by person is **24 km.**

A) 1 hour | B) 1 hour 30 min |

C) 2 hours | D) 2 hours 30 min |

A) 11.00 am | B) 12.30 pm |

C) 11.30 pm | D) 12.00 pm |

A) 100 km | B) 150 km |

C) 200 km | D) 250 km |