Question

A student wants to check six websites. Four of the websites are social and two are school related. After checking ju sites, she has to leave for school What is the approximate probability that she checked a social website first, then a school-related websites?

0.042
0.267
0.533
0.667

Answer 1

Option b

Explanation:

Given that there are 6 websites out of which four are social and two school related.

Total number of websites the student checked =2

Probability that she checked social website first= no of social websites/no of total websites

= 4/6= 0.667

Now available are 5 websites out of which 3 social and 2 school related

Prob for second school related =2/5 =0.40

Hence required probability = 0.667(0.40)

= 0.2668

=0.267

Answer 2

Total number of websites = 6
Number of school websites = 2
Number of social websites = 4

If she checks the social website first, the probability of checking a social website will be = 4/6

When one social website is checked, she is left with 3 social website and 2 school websites. So now the total number of websites is 5.

The probability that the second website she checks is school related = 2/5

The approximate probability that she checked a social website first, then a school-related website = 4/6 x 2/5 = 0.267

So option B gives the correct answer.