ล็อตเตอรี่ชนิดหนึ่งออกงวดละ 1000 ฉบ

A type of lottery issued each 1000 and for each period, there will be only one prize. In one installment, Mr. b, c and d buy a 6, 7, 12 and 15 Edition, respectively. If p is the probability that all four of these will not be justly prize. Find the value of a 1,000 p

Raffle off one of the periods of 1000 and each year there will be only one version only to be rewarded. In one period, Mr. A, B, C and D for 6, 7, 12 and 15 copies, respectively
, if p is the probability that the four men will not be awarded at all, what is the value of 1,000 p.

A kind of lottery ticket out each period 1000 original and each period will be only 1 version only to be awarded in the period one you, B, and 6, buy, and 7 12 15 copies, respectively.If P probability that both 4, this will not be a prize, and find the value of 1 000 P,,