$\Omega =\left\{\left(a,b\right):a,b\in \left\{0,1,2,3,4,5,6,7,8,9\right\}\right\}$  

$\overline{\overline{\Omega }}=10\cdot 10=100$  

a) A- suma otrzymanych liczb jest podzielna przez 7  

$A=\left\{\left(0,0\right),\left(0,7\right),\left(7,0\right),\left(1,6\right),\left(6,1\right),\left(2,5\right),\left(5,2\right),\left(3,4\right),\left(4,3\right),\left(5,9\right),\left(9,5\right),\left(6,8\right),\left(8,6\right),\left(7,7\right)\right\}$  

$\overline{\overline{A}}=14$  

$P\left(A\right)=\frac{14}{100}=\frac{7}{50}$  

b) B - iloczyn otrzymanych liczb jest podzielny przez 15

$B=\{\left(0,0\right),\left(0,1\right),\left(0,2\right),\left(0,3\right),\left(0,4\right),\left(0,5\right),\left(0,6\right),\left(0,7\right),\left(0,8\right),\left(0,9\right),$  

$\left(1,0\right),\left(2,0\right),\left(3,0\right),\left(3,5\right),\left(5,3\right),\left(4,0\right),\left(5,0\right),\left(5,6\right),\left(6,5\right),\left(6,0\right),$  

$\left(7,0\right),\left(8,0\right),\left(9,0\right),\left(9,5\right),\left(5,9\right)\}$  

$\overline{\overline{B}}=25$  

$P\left(B\right)=\frac{25}{100}=\frac{1}{4}$