Qand r are independent events. if p(q)= 1/8 and p(r)=2/5 find p(q and r).

1/20
To find P(Q and R), you have to multiply P(Q) by P(R) to get the probability that both events will occur. P(Q) = 1/8, and P(R) = 2/5, so when multiplied together, you get 2/40. This simplifies to 1/20, meaning P(Q and R) = 1/20.