Maria has a 30 min. work break. during the break, she'll walk 3 minutes to another floor, say hello to 4 different friends spending equal time with each, and walk back for 3 minutes. how long can she spend with each friend?

She can spend 6minutes with each friend.
Explanation step by step:
Maria has 30 min break, she walks 3 min to another floor- we have deduct that 3 min from 30 mi
30-3=27
Than she walks 3 min back to her floor
27-3=24
She has 24 minutes left which she equally divided between 4 friends
24:4=6
6 is the answer