Question

1. When Richard plays tennis, 65% of his serves go into the correct area of the court. If the first serve goes into the correct area, his chance of winning the point is 90%. If his first serve does not go into the correct area, Richard is allowed a second serve, and of these, 80% go into correct area. If the second serve goes into the correct area, his chance of winning the point is 60%. If neither serve goes into the correct area, Richard loses the point.
i. Draw a tree diagram to represent this information

Answer 1

see the attachment

Answer 2

Thanks! Hey there's one more part
iii. Find the conditional probability that Richard’s first serve went into the correct area, given that he loses the point.

Answer 3

And ii. Using your tree diagram, find the probability that Don loses the point

Answer 4

(ii) P required = 0.35*0.2 = 0.07
for the iii, i dunno sorry..

Answer 5

Ok. Thank you!

Answer 6

wait for (ii) it is 0.65*0.1 + 0.35*0.8*0.4+0.35*0.2 = 0.247

Answer 7

Yes, I thought so.

Answer 8

for iii, i was thinking it's still 0.65 :(

Answer 9

Are you sure though? I mean about the (ii)? Because aren't the chances of winning the point and the chances of the serves going in not related? I don't know...

Answer 10

the requirement is that he loses the point. so, he could lose the point even if he goes to the correct area..

Answer 11

it doesn't matter how many trials he try, you have to consider all the possible cases that he loses the point

Answer 12

Oh, Ok.