2016 · Q43
A person goes to a market between 4 p.m. and 5 p.m. When he comes back, he finds that the hour hand and the minute hand of the clock have interchanged their positions. For how much time (approximately) was he out of his house?
Elementary MathematicsTime, Speed and Distance
- A55.38 minutes
- B55.48 minutes
- C55.57 minutes
- D55.67 minutes
Explanation
Let t be minutes after 4:00; the hands move 6t° and 0.5t° respectively. Since they swap positions, together they sweep exactly 360°. Thus 6.5t = 360 and t ≈ 55.38 minutes, option A.