动物学家通过大量的调查估计出,某种动物活到20岁的概率是0.8,活到25岁的概率是0.5,活到30岁的概率是0.3,现年25岁到这种动物活到30岁的概率是( )
A.0.3
B.0.4
C.0.5
D.0.6
0 165506 165514 165520 165524 165530 165532 165536 165542 165544 165550 165556 165560 165562 165566 165572 165574 165580 165584 165586 165590 165592 165596 165598 165600 165601 165602 165604 165605 165606 165608 165610 165614 165616 165620 165622 165626 165632 165634 165640 165644 165646 165650 165656 165662 165664 165670 165674 165676 165682 165686 165692 165700 366461
A.0.3
B.0.4
C.0.5
D.0.6