Your Firm Receives 40 Cheques Per Month

Your firm receives 40 cheques per month.Of these,10 are for €1,200 and 30 are for €500.The delay for the €1,200 cheques is 4 days; the €500 cheques are delayed 6 days.What is the weighted average delay?

A) 4 days
B) 4.5 days
C) 5 days
D) 5.5 days
E) 6 days