If Ajay drives at 4/5th of his usual speed to his office, he is 6 minutes late. What is his usual time to reach his office?  Choices
A) 36 B) 24 C) 30 D) 18 E) 19
Explanation:   Let t be his usual time to reach his office and v be his usual speed.   v = d/t ……….(d is the distance Ajay travels while going to his office)   vt = d   At v1 = 4v/5 ; t1 = t + 6   4v/5 = d/(t + 6)   4v/5* (t + 6) = d   4v/5* (t + 6) = vt   On solving we get,   t = 24 minutes   ANSWER 24
<result>B</result>
If Ajay drives at 4/5th of his usual speed to his office, he is 6 minutes late. What is his usual time to reach his office?