Question

David can pack 132 cartoon of jar in one day and his assistant mark works one quarter as fast as David does .how many days would it take both of them working together to pack 660 cartoons

Answer 1

david 132
132/4  because he works as fast as divid
when they work together 132*132/4=165 a day
now 
165 in one day then
660 in .....?
660/165=4