Earl can stuff advertising circular into envelopes at the rate of 87 envelopes per minute . ellen requires a minute and a half to stuff the same number of envelopes. Working together, how long will it take earl and Ellen to stuff 580 envelopes?
a) 4 minutes b)5 minutes c)6 minutes d)3 minutes

• Earl can stuff advertising circular into envelopes at the rate of 87 envelopes per minute . ellen requires a minute and a half to stuff the same number of envelopes.
  Mean allen stuffs 87/1.5 = 58 envelopes per minute
  Together they stuff 87+58 = 145 enveopes per min
  they will take 580/145 = 4 minutes
• 13 years agoHelpfull: Yes(10) No(0)
• earl can envelope at d rate of 87 per minute
  and ellen can envelope at d rate of 87 per 1.5 munute or 3/2 minute
  or 87*(2/3)or 174/3 envelope per minute
  together they can envelope (87+174/3)or 435/3 envelope per minute
  so 580 envelope can be done in (580*3/435) or 4 minutes
• 13 years agoHelpfull: Yes(2) No(1)