work for __ days on the problem before coming up with a solution
難問に喜んで取り組む
relish a challenge
難問に対処する
cope with a knotty question
meet a challenge
難問に応じる
respond to the challenge
難問に思い悩む
worry about a problem
難問に悩まされる
be plagued by a problem
難問に手を焼く
have a hard time with a problem
難問に挑む
step up to a challenge
難問に日々直面する
face day-to-day challenges
難問に直面する
be confronted by a challenge
face a tough challenge
face with a difficult challenge
be faced with a challenge
be faced with a difficult question
難問に真っ向から立ち向かう
tackle the challenges head-on
難問に突き当たる
run head-on into trouble
難問に立ち向かう
face a tough challenge
face with a difficult challenge
難問の大きさ
size of the challenge
難問の追求
detective work(探偵のような)
難問は数多くあるけれど、根気良く探せば、お気に入りの物件はきっと見つかるはずだ。
There are many difficulties involved, but if you persevere in your search, you are bound to find a place that meets your liking.〔【出典】『外国人のための日本生活ガイド』(ひらがなタイムズ編)◆【出版社】株式会社ヤック企画 〕"YA05-019", "2516353"