Xiao Zhao is a triathlon enthusiast. If he spends 2 hours cycling, 3 hours running, and 4 hours swimming, the total distance traveled is 71 kilometers; if he spends 4 hours cycling and 2 hours running, Swimming for 3 hours, the total distance traveled is 94 kilometers, and it is known that his speed for the three events is an integer number of kilometers per hour, so how many kilometers per hour is the sum of his speed for the three events?
小赵是铁人三项运动的爱好者，如果他用2小时骑自行车，用3小时长跑，用4小时游泳，则行进总路程为71公里；如果他用4小时骑自行车，用2小时长跑，用3小时游泳，则行进总路程为94公里，又知道他进行三个项目的速度都是整数公里每小时，则他三个项目速度之和为多少公里/小时？
<gadget id="calculator">17 + 7 + 4</gadget>
<output>28</output>

<result>28</result>