OT - Calc of Avg temperature

[Clive George]

You were right first time with the first one - chance of mark winning =

12/30 = 6/15 = 0.4.

You failed on the chance of the shark winning, which is

(2/6 * 1) + (4/6 * 2/5) = 0.6.

(first card red or first black and second red. You failed to put in the proportion of times second card red is important.)

[Tim Streater]

Thanks.

[The Medway Handyman]

Assuming you get to pick the second. If your first choice is a red picture, you lose there & then.