Statistics And Probability Question 476
Question: A coin is tossed successively three times. The probability of getting exactly one head or 2 heads, is
[AISSE 1990]
Options:
A) $ \frac{1}{4} $
B) $ \frac{1}{2} $
C) $ \frac{3}{4} $
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
-
Required probability $ ={}^{3}C_1{{( \frac{1}{2} )}^{1}}.{{( \frac{1}{2} )}^{2}}+{}^{3}C_2{{( \frac{1}{2} )}^{2}}.{{( \frac{1}{2} )}^{1}}=\frac{3}{8}+\frac{3}{8}=\frac{6}{8}=\frac{3}{4} $ .
BETA
