Răspuns:
1/21·3/55·11/23·7/2=1/230
se simplifica termenii pe diagonala
ex 3 cu 21,11 cu 55 etc
1/21 × 3/55 × 11/23 × 7/2 =
1/7 × 1/5 × 1/23 × 7/2 =
1/5 × 1/23 × 1/2 =
(1 × 1 × 1)/(5 × 23 × 2) = 1/230
