Question

A survey was undertaken at Aphane High School to determine the proportion of learners that had Facebook and Openstudy accounts. A random sample showed the following

Answer 1

 If a learner had a OS account then they also had a Facebook account.
 If a learner didn't have a OS account, then there was a 90% chance they had a Facebook account.
 The probability that they had a OS account was 0,36

Answer 2

1)Draw a Venn diagram depicting the information given above.
2)Calculate
a)The probability of having a Facebook account.
b) The probability of having neither a Facebook account nor a Openstudy account

Answer 3

probability of having a Facebook account=0.36*1+(1-0.36)*0.9 =0.936

The probability of having neither a Facebook account nor a Openstudy account
=1-0.936
=0.064