Japanese divides into 10 to express proportion. 十分(juubun) means 100% literally. other examples, 五分(gobu) 50% 八分(hachibu) 80% 十二分(juunibun) more than 100%, too enough

I think you've had enough to drink. - もう十分に飲んだでしょ。 Do you have enough time for breakfast? - 朝食のための十分な時間がありますか。 A used PC is good enough for me. - 中古パソコンで私には十分です。 By the way "gobu" and "hachibu" are not too close to expressing of the word "enough"! The scale of expressing of "taste saturation" is here: 1. so so 2. well 3. good 4. perfect 5. too much 6. enough 7. too enough 8. ??!!!?? (without a word)

十分な+　noun　　十分な食料が、あります。 十分に＋　verb 食料は、十分にあります。