两辆车同时从同一个位置向同一个方向行驶。第一辆车的速度为 50 公里/小时，第二辆车的速度为 60 公里/小时。两车相距20公里所用的小时数是_________。
注意：这是数字类型问题。
(一) 1
(乙) 2
(三) 3
(四) 6答案：(乙)
解释：给定两辆车同时从同一地点向同一方向行驶，速度分别为 50 公里/小时和 60 公里/小时。
因此，1小时后，
distance traveled by first car (with speed of 50 km/h) = 50*1 = 50 km
And, distance traveled by second car (with speed of 60 km/h) = 60*1 = 60 km
So, distance between these cars = 60 - 50 = 10 km 2小时后，
distance traveled by first car (with speed of 50 km/h) = 50*2 = 100 km
And, distance traveled by second car (with speed of 60 km/h) = 60*2 = 120 km
So, distance between these cars = 120 - 100 = 20 km 替代方式：
→ (distance traveled by second car) - (distance traveled by first car) = 20 km
→ (S2*T) - (S1*T) = 20
→ (60*T) - (50*T) = 20
→ 10*T = 20
→ T = 2 因此，选项(B)是正确的。这个问题的测验