Answer:
2/7
Step-by-step explanation:
If two events A and B are independent, then P(A and B)=P(A)P(B).
So since Q and R are independent, then P(Q and R)=P(Q)P(R).
Let's substitute and evaluate:
[tex]P(Q\text{ and }R)=P(Q)\cdot P(R)=\frac{4}{7} \cdot \frac{1}{2}=\frac{4}{14}[/tex].
Both 2 and 14 are divisible by 2, so to reduce 4/14 we could divide top and bottom by 2:
4/14=(4/2)/(14/2)=2/7
