Tony,

yup, confusing isnt it :? you have got me wondering if I have got it right now

My greater than 1 in 5 chance was actually the chance of pulling a ball that was consecutive to one of the 5 previously drawn balls, assuming those previous 5 balls were not themselves consecutive (and assuming they were neither number 1 or 49). I did not add to this the probability of the previous balls being consecutive.

The way I tackled this is as follows:

Ball 1 is drawn.

Probability of drawing a consecutive ball on ball 2 is now 2/48 (assuming ball 1 was not 1 or 49). 2/48 = 0.04 or 4%.

If ball 2 is not consecutive, the chance of pulling consecutive ball for ball 3 is now 4/47 (with the same 1 and 49 caveat). 4/47 = 0.085 or 8.5%.

If 1 2 and 3 are not consecutive, the chance of pulling a consecutive ball on the 4th draw is now 6/46. 6/46 = 0.13 or 13%.

and so on until ball 6 is drawn. If balls 1 to 5 do not make 2 consecutive numbers, then 10 balls of the remaining 44 balls can be drawn to make two consecutive numbers. Thus 10/44 = .227 or 22.7%.

Thus if balls 1 to 5 are not consecutive, there is a greater than 1 in 5 chance that the 6th ball drawn will be consecutive to one of the previously drawn 5 balls.

I think our discrepancy arises because I have presented the chance of the last ball only, while you have been better at maths and presented the probability of all options :?:

I also am not an expert in probability

, if I was I would be in Vegas, or possibly Blackpool waiting for the mega-casino :twisted:

Steve.