1) 10*10=100 issues {01....... 99}
2. 99/10=9
P(X=9*k)=9/100=0.009=0.9%
3) P(X)=1/10+(9/10)*(1/10)+(1/10)*(1/10)=19/100=0,19=19%
4) 99/7=14 il y a 14 multiples de 7
P(7)=14/100=0.14
5) 99/5=19 il y a 19 multiples de 5
P(5 )=19/100=0.19
6) P(X) =1-P(7)-P(5)=0.67