题目
某人打靶击中的概率为(3)/(4),如果直到射中靶为止,则射击次数为5的概率为().A. ((3)/(4))^5B. C_5^4((3)/(4))^4((1)/(4))C. C_5^1((3)/(4))((1)/(4))^4D. ((3)/(4))((1)/(4))^4
某人打靶击中的概率为$\frac{3}{4}$,如果直到射中靶为止,则射击次数为5的概率为().
A. $\left(\frac{3}{4}\right)^5$
B. $C_5^4\left(\frac{3}{4}\right)^4\left(\frac{1}{4}\right)$
C. $C_5^1\left(\frac{3}{4}\right)\left(\frac{1}{4}\right)^4$
D. $\left(\frac{3}{4}\right)\left(\frac{1}{4}\right)^4$
题目解答
答案
D. $\left(\frac{3}{4}\right)\left(\frac{1}{4}\right)^4$