Walking with 4/5 of my usual speed, I miss the bus by 6 minutes. What is my usual time?	Choose the correct choice from the following options
A) 16 min  B) 26 min  C) 34 min  D) 24 min  E) 12 min

Rationale: "speed ratio = 1 : 4 / 5 = 5 : 4 time ratio = 4 : 5 1 - - - - - - - - 6 4 - - - - - - - - - ? è 24 answer : d"
Answer: D