Taro and Jiro left P at the same time and made a round trip between P and Q.
Jiro reached P three minutes later after Taro reached P.
The ratio of speed of Taro and Jiro is 3 : 2.
(1) Find the speed of Taro in meter per minute.
(2) Find the time of minutes and seconds when two people passed each other after they left P.
Answer
(1) 240 m/m
(2) 3 minutes 36 seconds
Solution
(1) The ratio of distance is 3 : 2 which is the same as the speed ratio of Taro and Jiro.
Jiro moved the distance of 3 -2 = 1 in 3 minutes.
Jiro took 3 minutes × 3 = 9 minutes to make a round trip between P and Q.
Taro took 9 - 3 = 6 minutes.
Thus the spped of Taro is 720 × 2 / 6 = 240 m/m.
(2) The speed of Jiro is 240 × 2/3 = 160 m/m.
720 × 2 / (240 + 160) = 3.6 minutes = 3 minutes 36 seconds.
