# QA – Placement Quizzes | Time Speed Distance | Question 13

Walking 3/4^{th} of his speed, a person is 10 sec late to his office. Find his usual time to cover the distance?**(A)** 40 sec**(B)** 25 sec**(C)** 45 sec**(D)** 30 sec**Answer:** **(D)****Explanation:** Say distance =x meters

usually he takes t sec

usual speed v = x/t m/sec ———(1)

3v/4 = x/(t+10) —————(2)

(1)/(2)

=> 4/3 = (t+10)/t

=>t =30 sec