Horace and School Conditional Probability (Part I)
Horace either walks or runs to the bus stop. If he walks he catches the bus with probability . If he runs he catches it with probability . He walks to the bus stop with a probability of . Find the probability that Horace catches the bus.
The answer is 0.54.
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
W : event that Horace walks to the bus
R : event that Horace runs to the bus (i.e., W c or Horace doesn't walk)
B : event that Horace catches the bus
P ( B ) = P ( W ) P ( B ∣ W ) + P ( R ) P ( B ∣ R )
P ( B ) = 0 . 4 × 0 . 3 + 0 . 6 × 0 . 7
∴ P ( B ) = 0 . 5 4