он мог решить такие задачи, когда е

он мог решить такие задачи, когда ему было 10 лет. он смог бы решить такие задачи, когда ему было 10 лет.

Результаты (английский) 1:

He could solve such tasks when he was 10 years old. He could solve such tasks when he was 10 years old.

Результаты (английский) 2:

he could solve such problems, when he was 10 years old. he was able to solve such problems, when he was 10 years old.

Результаты (английский) 3:

he could solve such tasks when he was 10 years old. he would be able to solve such tasks when he was 10 years old.