Earl can stuff advertising circulars into envelopes at the rate of 36 envelopes per minutes and Ellen requires a minutes and half to stuff the same number of envelops.Working together,how long will it take Earl and Ellen to stuff 180 envelopes  Choose the correct choice from the following options:
A) 6 minutes
B) 5 minutes
C) 7 minutes
D) 3 minutes
E) 4 minutes

Rationale: earl takes 1 min . for 36 envelopes . ellen takes 3 / 2 mins for the same . so ellen can stuff ( ( 36 ) / ( 3 / 2 ) ) in 1 min . i . e . , 24 envelopes a min . so both of them when work together can stuff 36 + 24 = 60 envelopes in 1 min . for 180 envelopes they will take 180 / 60 mins . i . e . , 3 mins . answer : d
Answer: D