A student wants to check six websites. Four of the websites are social and two are school-related. After checking just two sites, she has to leave for school.

What is the approximate probability that she checked a social website first, then a school-related website?

A. 0.042
B. 0.267
C. 0.533
D. 0.60



Answer :

To determine the probability that the student checked a social website first and then a school-related website, follow these steps:

1. Identify the total number of websites and categorize them:
- Social websites: 4
- School-related websites: 2
- Total websites: 6

2. Calculate the probability of checking a social website first:
- There are 4 social websites out of the 6 total websites.
- Probability of picking a social website first = Number of social websites / Total websites
- This gives us: [tex]\( \frac{4}{6} = \frac{2}{3} \approx 0.6667 \)[/tex]

3. Calculate the probability of checking a school-related website second, given the first was a social website:
- After choosing a social website first, we have 5 websites left (3 social and 2 school-related).
- Probability of picking a school-related website second = Number of remaining school-related websites / Remaining total websites
- This gives us: [tex]\( \frac{2}{5} = 0.4 \)[/tex]

4. Calculate the combined probability of both events occurring:
- The probability of both events (checking a social website first and a school-related website second) can be found by multiplying the individual probabilities together.
- Combined probability = Probability of checking a social website first * Probability of checking a school-related website second
- This gives us: [tex]\( 0.6667 \times 0.4 = 0.2667 \)[/tex]

Therefore, the approximate probability that the student checked a social website first and then a school-related website is 0.267.

So the correct option is:
0.267