It takes an older computer 4 times as long to send out a company's email as it does a newer computer. Working together, it takes the two computers 10 minutes to send out the email. How long will it take the newer computer to send out the email on its own?

1 Answer
Oct 27, 2017

12.5 minutes

Explanation:

Suppose the old computer can send out n e-mails per minute
the new computer can send out 4n e-mails per minute.

Working together they could send out
XXXn+4n=5n e-mails/minute

and in 10 minutes they could send out
XXX(5n e-mails minute)×10 minutes=50n e-mails

Since the new computer can send out 4n e-mails per minute,
in order to send out 50n e-mails
the new computer would require
XXX50n emails4n emials minute=12.5 minutes