你随便帮我点个菜就可以了。

Nǐ suíbiàn bāng wǒ diǎn gè cài jiù kěyǐ le.

Order me any dish you want.

随便你。

Suíbiàn nǐ.

It's up to you.

那条选择题太难，我最后随便选了一个答案。

Nà tiáo xuǎnzétí tài nán, wǒ zuìhòu suíbiàn xuǎn le yí gè dá'àn.

That multiple choice question is too hard, in the end I chose an answer at random.