If you give up without passing a difficult exam, you'll never make up for lost time.
"難関試験に合格出来ないまま諦めたら損失時間を取り戻せない"
- If you give up without passing a difficult exam, you'll never make up for lost time.
recoup lost timeを使いたいです。
-> "recoup" lost time はみたことありません。よく、recover lost time か regain lost time それか make up for lost time をみます。でも、意味はあまり変わらないと思います。
- If you give up on passing a difficult exam you won't be able to recoup lost time.
- ... you won't be able to recover lost time.
"You'll never get the time back if you give up on a difficult test."
"If you give up on a hard test without passing, you'll never recoup the time lost."
"You'll never get the time back if you give up on a difficult test."
"you'll never get ~ back" 「〜取り戻せない」
the time 「時間」・「損失時間」
"if you give up" 「諦めたら」
"difficult test" 「難関試験」
"If you give up on a hard test without passing, you'll never recoup the time lost."
"hard test" 「難しい試験」
"without passing" 「合格しないまま」
"you'll never recoup ~" 「〜取り戻せない」
"the time lost "「損失時間」
アメリカ合衆国 
オーストラリア 
