1.6.60 Fields, Groups, Rings

condition: Let \( \varphi-th m o m o rph i m ~ \mathbb{Z} / 30 \mathbb{Z} \) in \( \mathbb{Z} / 6 \mathbb{Z} \) such that \( \operatorname{Ker}(\varphi)=\{0,6,12,18,24\}\). Prove that \( \varphi- \) is surjective. What possible values ​​can \( \varphi(1) \) take?