In a series of n independent trials, the probability of a success at each trial is p. If R is the random" variable denoting the total number of successes, state the probability that Rr. State also the mean and variance of R. A certain variety of flower seed is sold in packets containing 1000 seeds. It is claimed on the packet that 40% will bloom white and 60% will bloom red. This may be assumed to be accurate. Five seeds are planted. Find the probability that

(a) exactly three will bloom white,

(b) at least one will bloom white. 100 seeds are planted. Use the normal approximation to estimate the probability of obtaining between 30 and 45 (inclusive) white flowers.