First Jim and Jeanne walks across the bridge, it takes 2 minutes.

Jim walks back with the torch light, which takes 1 minute.

Then Louis and Anne walk on the bridge, which takes 10 minutes.

Jeanne comes back with the torch light, it takes 2 minutes.

Finally Jim and Jeanne walks across the bridge, which takes 2 minutes.

Total = 2 + 1 + 10 + 2 + 2 = 17 minutes

1113122110

In given series 2nd number gives number of which digits present in the 1st number and so on continues for 3rd ,4th,...

Here 1st no. has only one zero, so 2nd no. is 10 and 2nd no. has one 1 and one 0,so 3rd no. is 1110, so like that 5th no. has one 1,one 3,one 2,two 1's and one 0.So the next no. is 1113122110.