a) Given the red shows a 6, there are six points (r,b) in the sample space all

equally likley (6,1) (6,2) ... (6,6)

Of these six (6,4), (6,5) and (6,6) have a total greater than or equal to 10,

so the required prob

p = (#favourable cases)/(total ' of equally likley cases) =3/6=1/2

b) The sample space is: (6,1), (6,2), ..., (6,6), (1,6), (2,6), ..., (5,6).

The outcomes that satisfy the condition are:

(6,4), (6,5), (6,6), (4,6), (5,6)

a total of 5, out of a grand total of 11 (don't count (6,6) twice!), so the required

prob is

p = 5/11

RonL