10th Class Mathematics Probability Question Bank MCQs - Probability

In a family of 3 children, the probability of having at Least one boy is:

A) \[\frac{7}{8}\]

B) \[\frac{1}{8}\]

C) \[\frac{5}{8}\]

D) \[\frac{3}{4}\]

Correct Answer: A

Solution :

[a] Let B denotes boy and 6 denotes girl.

\[\therefore \] Total possible outcomes are

\[\{BBB,BBG,BGB,GBB,BGG,GBG,GGB,GGG\}\]i.e., 8.

Favourable outcomes of having atleast one boy are

\[\{BBB,BBG,BGB,GBB,BGG,GBG,GGB\}\]ie., 7.

\[\therefore \] Required probability\[=\frac{7}{8}\]