Ned is an explosives specialist racing to deactivate a time bomb on the top floor of a building. The building has twenty flights of stairs to the top floor, and Ned can run up one flight of stairs in eleven seconds. The time bomb has 72 seconds left on the timer, and Ned has spent 165 seconds running up the stairs. How many seconds will Ned have to diffuse the bomb when he reaches it? Give me reasons, before answering the question
Ned has gone up 165 / 11 = 15 flights of stairs. Thus, he has 20 - 15 = 5 flights of stairs left to run up. He will spend 5 * 11 = 55 seconds running up the remaining stairs to the bomb. Therefore, he will have 72 - 55 = 17 seconds to defuse the bomb. So the final answer is 17.