This is the 558th most frequent Ukrainian word.
наскільки
"How much" or "to what extent."
Here, 'наскільки' is used to ask about the degree or extent of difficulty.
Наскільки важко виконати це завдання?
How difficult is it to complete this task?
In this sentence, 'наскільки' expresses the extent or degree of how quickly something was done.
Я здивований, наскільки швидко ти завершив цю роботу.
I am surprised at how quickly you finished this work.
Here, 'наскільки' is used to evaluate the degree of influence.