All of these sentences are grammatically correct.👍 Of course, as you must obviously know, in natural conversation you would never answer in this way... You would simply say something like: "...about 5 minutes..."

Yes 🙌🏻 Grammatically is correct. However, to have a clear idea 💡 about both so “will”: used for formal or informal that is unplanned and “going to” used for informal planned so in this situation at it seems more casual you can use “ going to” How long is it going to take to drink a beer? About 5 minutes ( as is the informal situation and as a short answer since English especially American accent is about to make it easy ) I hope my answer light 💡 up your question. Thanks & wish you the best 🌟 in your learning Have a great journey ✌️💫🙏

yes!! You can use gonna instead of “going to” if you want to sound more casual too.

Yep! Both sentences are correct. 😊