Probability Question 93
Question: If four vertices of a regular octagon are chosen at random, then the probability that the quadrilateral formed by them is a rectangle is
[AMU 1999]
Options:
A) $ \frac{1}{8} $
B) $ \frac{2}{21} $
C) $ \frac{1}{32} $
D) $ \frac{1}{35} $
Show Answer
Answer:
Correct Answer: D
Solution:
Here only 2 rectangles are formed ADEH, GFCB.
Number of favourable cases = 2 and total number of cases $ {{=}^{8}}C_4 $
Required probability = $ \frac{2}{^{8}C_4} $
$ =\frac{1}{35} $ .
BETA
