10. If she (take) the bus, she (not/ arrive) on time.

10. If she had taken the bus, she wouldn't have arrived on time.

В условных предложениях третьего типа (Type 3) в придаточном предложении (if-clause) используется Past Perfect, а в главном предложении (main clause) используется would have + Past Participle.

Ответ: If she had taken the bus, she wouldn't have arrived on time.