DD.37 Another triathlon race

Taro and Jiro participated in the competition of the triathlon.

A triathlon is a game which carry out three athletic games in order of swimming, a bicycle (49 km), and marathon (20 km), and all athletes compete for speed there.

In a swimming race, the ratio of the speed of Taro and Jiro is 15 : 13 and there is distance difference of 12 m in one minute.
It was 6 minutes after since Taro begins a bicycle race that Jiro made a goal by swimming.
In the bicycle race, the ratio of the speed of Taro and Jiro was 5 : 7.
Since the tire was flat on the way, Jiro took 12 minutes and 15 seconds for the repair.
It was 9 minutes and 45 seconds after Jiro started marathon game when Taro made a goal by the bicycle.
Answer the following questions.

(1) Find the speed per minute at which Taro swims.

(2) Find the distance of the swimming race.

(3) Find the speed per hour of Jiro in a bicycle race.

(4) In the last marathon, 7.2 km from the start is the course of ascent and remaining 12 km is flat course.
Through the course of ascent, the ratio of the speed of Taro and Jiro is 6 : 5.
Taro was able to shorten the time difference with Jiro in the course of this ascent for 5 minutes.
Find the speed per minute when Jiro runs a flat course to make a goal ahead of Taro.
The ratio of the speed in the course of ascent and flat of Taro is 9 : 10.



Answer
(1) 90 m/m
(2) 3510 m
(3) 42 km/h
(4) 287 m/m