Walking with 3/5 of my usual speed, I miss the bus by 5 minutes. What is my usual time?
Choose the correct choice:
A) 16 min	B) 26 min	C) 34 min	D) 20 min	E) 15 min

Rationale: "speed ratio = 1 : 3 / 5 = 5 : 3 time ratio = 3 : 5 1 - - - - - - - - 5 3 - - - - - - - - - ? è 15 answer : e"
Answer: E