HMMT 十一月 2016 · THM 赛 · 第 2 题
HMMT November 2016 — THM Round — Problem 2
题目详情
- Point P is located 600 miles West of point P . At 7:00 AM a car departs from P and drives East at 1 2 1 a speed of 50 miles per hour. At 8:00 AM another car departs from P and drives West at a constant 2 speed of x miles per hour. If the cars meet each other exactly halfway between P and P , what is the 1 2 value of x ?
解析
- Point P is located 600 miles West of point P . At 7:00 AM a car departs from P and drives East at 1 2 1 a speed of 50 miles per hour. At 8:00 AM another car departs from P and drives West at a constant 2 speed of x miles per hour. If the cars meet each other exactly halfway between P and P , what is the 1 2 value of x ? Proposed by: Eshaan Nichani Answer: 60 Each car meets having traveled 300 miles. Therefore the first car traveled for 300 / 50 = 6 hours, and so the second car traveled for 5 hours. The second car must have traveled 300 / 5 = 60 miles per hour.