CAT 2020 Slot 3 QA Question 10: 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 o

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 o

Accepted Answer

Let her usual travel time be $t$ hours and the distance be $d$ km.
$d = 40t$
$\dfrac{d}{35} = t + \dfrac{6}{60}$
$\Rightarrow \dfrac{40t}{35} = t + \dfrac{1}{10}$
$\Rightarrow \dfrac{8t}{7} - t = \dfrac{1}{10}$
$\Rightarrow t = \dfrac{7}{10}$ hour = 42 minutes
So, $d = 40 	imes 0.7 = 28$ km.
On tha