The distance between X point and Y point is 40km.
Taro departs from X point by car and he moves back and forth between XY.
Jiro departs from Y point by motorbike and he moves back and forth between XY.
Two persons' speed is fixed, respectively.
5 minutes after Taro left X point, Jiro left Y point.
When Taro arrived at Y point, he took a rest for 10 minutes and left Y.
When Jiro arrived at X point, he took a rest for 5 minutes and left X.
Two persons met 1st time in the middle of moving forth and it was 32 minutes after Taro left X point.
Two persons met 2nd time in the middle of returning and it was the place 32 km away from Y point.
Find the speed per hour of A and B, respectively.
Answer
Taro : 48km/h
Jiro : 32km/h
Solution
Taro took a rest for 10 minutes before the 2nd meeting with Jiro after his leaving.
Moreover, Jiro left Y 5 minutes after Taro's leaving and he took a rest for 5 minutes before the 2nd meeting with Taro.
Therefore, the time while both of them moved until the 2nd meeting after Taro's leaving is same.
By the time of the 2nd meeting, Taro moved 40 + 32 = 72km and Jiro moved 40 + (40 - 32) = 48 km.
The ratio of the speed of Taro and Jiro is the same as that of the distance and it is 72 : 48 = 3 : 2.
Two persons moved 40 km in all after Taro left X point.
The speed per hour of Tar and Jiro is set to 3 and 2, respectively.
3 × 32/60 + 2 × 27/60 = 40km.
5/2 = 40 km.
1 = 16 km/h.
3 = 16 × 3 = 48 km/h and 2 = 16 × 2 = 32 km/h.
Taro departs from X point by car and he moves back and forth between XY.
Jiro departs from Y point by motorbike and he moves back and forth between XY.
Two persons' speed is fixed, respectively.
5 minutes after Taro left X point, Jiro left Y point.
When Taro arrived at Y point, he took a rest for 10 minutes and left Y.
When Jiro arrived at X point, he took a rest for 5 minutes and left X.
Two persons met 1st time in the middle of moving forth and it was 32 minutes after Taro left X point.
Two persons met 2nd time in the middle of returning and it was the place 32 km away from Y point.
Find the speed per hour of A and B, respectively.
Answer
Taro : 48km/h
Jiro : 32km/h
Solution
Taro took a rest for 10 minutes before the 2nd meeting with Jiro after his leaving.
Moreover, Jiro left Y 5 minutes after Taro's leaving and he took a rest for 5 minutes before the 2nd meeting with Taro.
Therefore, the time while both of them moved until the 2nd meeting after Taro's leaving is same.
By the time of the 2nd meeting, Taro moved 40 + 32 = 72km and Jiro moved 40 + (40 - 32) = 48 km.
The ratio of the speed of Taro and Jiro is the same as that of the distance and it is 72 : 48 = 3 : 2.
Two persons moved 40 km in all after Taro left X point.
The speed per hour of Tar and Jiro is set to 3 and 2, respectively.
3 × 32/60 + 2 × 27/60 = 40km.
5/2 = 40 km.
1 = 16 km/h.
3 = 16 × 3 = 48 km/h and 2 = 16 × 2 = 32 km/h.
