Орлов...................0.......1......2
Вер-ть..................1/4..2/4....1/4
Выстрелов.............0......1.......2
Вер-ть промазать..1...1/5....1/25

Ответ (1/4)*1 + (2/4)*(1/5) + (1/4)*(1/25)