At Sanger’s auto garage, 40% of the cars brought in for service need an oil change. Of the cars that need oil changes, 30% also need a tire rotation. Find the probability that a car that comes into the auto garage needs both an oil change and a tire rotation.

Question

anonymous · Answer

A.
	
0.10
B.
	
0.12
C.
	
0.70
D.
	
0.75

bibby · Answer

In probability of usually means multiplication.

What is 30% of 40%?

anonymous · Answer

Im doing conditional probability

bibby · Answer

That isn't the right answer chaz

anonymous · Answer

0.75

bibby · Answer

how'd you get that?

anonymous · Answer

?

bibby · Answer

I'm not going to give you the answer.

bibby · Answer

Provide your work and logic

anonymous · Answer

ok?

anonymous · Answer

im not understanding conditional geometry...

anonymous · Answer

P(Oil Change)=.4
P(Tire Rotation|Oil Change)=.3

P(A|B) = P(A and B)/P(B)

anonymous · Answer

.75 is the correct answer

anonymous · Answer

but its not :(

anonymous · Answer

im taking a quiz and it said it was incorrect :(

anonymous · Answer

oops, i mean .12

anonymous · Answer

ok thanks :D

bibby · Answer

30% of the 40% that require the thing = 0.3*0.4

bibby · Answer

Thanks for the explanation. You people are ruining this site

anonymous · Answer

.3=P(A and B)/.4 => P(A and B) = .3*.4 = .12

anonymous · Answer

does that make sense?