‘Bet’ is slang which, in this context, means ‘sure thing’ or ‘there is no doubt, so you can bet on it’. ‘10 out’ means they are 10 minutes away from where they’re going

'Bet' is a slang term expressing approval, agreement, etc. Like 'you can bet on it,' meaning something is a good idea or a sure thing. '10 out' means the person is 10 minutes away or 10 minutes 'out' from the destination they are headed towards. Also this is heavy short hand/slang. To me, '10 out' has a military sort of feel to it.