Question

Vimla starts for office every day at 9 am and reaches exactly on time if she drives at her usual speed of 40 km/hr. She is late by 6 minutes if she drives at 35 km/hr. One day, she covers two-thirds of her distance to office in one-thirds of her usual time to reach office, and then stops for 8 minutes. The speed, in km/hr, at which she should drive the remaining distance to reach office exactly on time is

• A. 29
• B. 27
• C. 28
• D. 26

Answer 1

Answer: (C)

28

Answer 2

The correct answer is (C): $28$
Let the original time taken by Vimla be $t$ minutes $\frac{40t}{60} = \frac{35×(t+6)}{60}$

$⇒ t=35×\frac{6}{5}=42$ $min$

The distance to office = $28$ $km$

Required answer = $\frac{28×\frac{1}{3}}{42×\frac{2}{3}-8}×60 = 28$ $kmph$