Find the least common denominator of 11/12 and 3/4

Hi my sisters and brothers can tell me the answer because i don’t understand the question

You have 12 balloons to blow up for your birthday party. you blow up 1/3, and your friend blows up 5 of them. what fraction of the baloons still need blowing up

30 ! the graph shows the number of siblings different students have. select from the drop-down menus to correctly complete the statement.