four people need to cross a bridge at night.the bridge is only strong enough to hold at most two people at once because it is night a flashlight must be used for all crossings it takes mr. A 10 min to cross .mr B 5min to cross.mr.C 2 min to cross mr.D 1 min to cross.if two of them cross at the same time they must walk at the slower man's pace.how can you get every one to cross the bridge in 17 mins??

A takes 10 minutes to cross the bridge
B takes 5 minutes to cross the bridge
C takes 2 minutes to cross the bridge
D takes 1 minute to cross the bridge
Step 1: C and D cross the bridge in 2 minutes. D stays, and C returns in 2 minutes.
Step 2: A and B cross the bridge in 10 minutes. Now D returns in 1 minute.
Step 3: C and D cross the bridge in 2 minutes.
Therefore, total time taken = 2 + 2 + 10 + 1 + 2 = 17 minutes
Hope this helps!