Statistics And Probability Question 68

Question: A coin is tossed 3 times. The probability of obtaining at least two heads is or Three coins are tossed all together. The probability of getting at least two heads is

[MP PET 1995]

Options:

A) $ \frac{1}{8} $

B) $ \frac{3}{8} $

C) $ \frac{1}{2} $

D) $ \frac{2}{3} $

Show Answer

Answer:

Correct Answer: C

Solution:

  •         Required probability  $ ={{( \frac{1}{2} )}^{3}}.{}^{3}C_2+{{( \frac{1}{2} )}^{3}}.{}^{3}C_3=\frac{4}{8}=\frac{1}{2}. $                                  {Here at least two heads means two heads or three heads}.