Anyone here is good at Probability? I can't get the answer for this question...

**daominhhai129** · September 14th 2009, 11:52 AM

please helps me to solve the question 3c. The answer is 2/9 but i do not know how to get that...T_T

**Plato** · September 14th 2009, 12:06 PM

Originally Posted by daominhhai129

please helps me to solve the question 3c. The answer is 2/9 but i do not know how to get that...T_T

Let R be a right move: $P(R)=\frac{2}{6}$ .
Let L be a left move: $P(L)=\frac{4}{6}$ .
To end at B in three moves, we need RRL, RLR, or LRR.
Each of those has the same probability and $P(RRL)=\frac{2}{6}\cdot \frac{2}{6}\cdot\frac{4}{6}$

**daominhhai129** · September 14th 2009, 12:12 PM

thank you very much..but my answer sheets say it's 2/9....i don't know whether my answer sheet is wrong or i do wrongly...

**Plato** · September 14th 2009, 12:20 PM

Originally Posted by daominhhai129

my answer sheets say it's 2/9..

No the answer sheet is correct.
$3P(RRL)=3\left(\frac{2}{6}\cdot \frac{2}{6}\cdot\frac{4}{6}\right)=\frac{2}{9}$

**daominhhai129** · September 14th 2009, 12:22 PM

oh haha..thank you thank you..i'm so stupid..ya..now i can understand..thanks

Thread: Anyone here is good at Probability? I can't get the answer for this question...

LinkBack

Thread Tools

Display

Anyone here is good at Probability? I can't get the answer for this question...

Similar Math Help Forum Discussions

Confirm answer: probability question

Stumped on how to answer multi step probability question.

Probability Question - Independence , Any answer is appreciated...

Probability - not good with, can you help.

Probability of a good queue

Search Tags