Question

In a survey, following data was recorded:

$\begin{array}{cccc}\text{No.of girls in a family}& \text{2}& \text{1}& \text{0}\\ \text{No. of families}& \text{475}& \text{814}& \text{211}\end{array}$

A family is chosen at random. Find the probability that the family has

(i) Two girls
(ii) No girls
(iii) At least one girl

• A.
  
  $\frac{19}{1500},\frac{195}{1500},\frac{1289}{1500}$
  
• B.
  $\frac{223}{1500},\frac{19}{1500},\frac{815}{1500}$
  
• C.
  
  $\frac{19}{60},\frac{211}{1500},\frac{1289}{1500}$
  
• D.
  None of the above

Answer 1

The correct option is C


$\frac{19}{60},\frac{211}{1500},\frac{1289}{1500}$

Add all the members of the family to get the total number of families.

$475+814+211=1500$

Probability that the family has two girls $=\frac{475}{1500}=\frac{19}{60}$

Probability that the family has no girls $=\frac{211}{1500}$

Probability that the family has at least one girls =One girl + Two girls

$=\frac{814}{1500}+\frac{475}{1500}=\frac{814+475}{1500}=\frac{1289}{1500}$