SAP Softwareentwickler interview questions

No such unexpected questions came up in technical round related to C/C++/DS as I was prepared for it. But I was asked a puzzle which surprised me but I answered it after giving some thought. The question was, "Suppose there is a bridge with a time bomb planted on it which will explode in 17 mins. There are four persons namely A,B,C and D on one side of the bridge who need to be evacuated, who take 10 min, 5 min, 2 min and 1 min respectively. The is only one torch which needs to be carried while crossing the bridge and at most two persons can cross at a time and they take the maximum time out of the two.Suggest a way so that all of them cross the bridge before it explodes.

Continuation of asking knowledge based questions after my confession of unfamiliarity.