Explicație pas cu pas:
a) (4/10) *(3/9)=(2/5)*(1/3)=2/15
b)(6/10) *(5/9)=(3/5) *(5/9)=3/9=1/3
c)(4/10)*(6/9)=(2/5) *(2/3) =4/15
d)(6/10)*(4/9)=(3/5) *(4/9) =(1/5)*(4/3) =4/15 de asteptat, ca prcedentul
e)insumam a) si b) 2/15+1/3=7/15
f) insumam c) si d) 4/15+4/15=8/15
se observa ca e) si f) sunt evenimente complementare, deci toata probleam este bine rezolvata