Question

There are 24 pictures on a roll film. Adelle had 84 pictures from her trip home she said that 12 other pictures were spoiled. How many rolls of film did Adelle use?

Answer 1

Adelle took 84+12, or 96 pictures in all, including the unspoiled ones too. And since there are 24 pictures in each roll, you divide 96 by 24.
96/24 gives you 4.
So Adelle used 4 rolls of film. 
Hope this helps.