Another probability problem

[mathwhizwannabe]

The probability of Carl beating Zack at chess is 3/10. The probability of Carl beating Leon at chess is 3/4. (Assume all the games are independent events.) If Carl plays one game with Zack and one with Leon, find the probability that Carl

a. wins both games
b. loses both games
c. Using the results above, how can you find the probability that Carl wins at least one game?

I got:

a. 9/40
b. 7/40
c. 33/40

I am pretty sure I did a and b right, but I am not sure of c. If c is not right, could I please have some help?

 

[stapel]

Aside from the possibility of being disheartened if the first game is lost and thus playing less well on the second game, we should be able to treat these events as being independent.

a) (3/10)(3/4) = 9/40

b) (7/10)(1/4) = 7/40

c) 1 - 7/40 = 33/40

I think your answers are correct.



Eliz.

 

[mathwhizwannabe]

Thanks so much!