Homework Help: math/117

Posted by Angela on Sunday, December 4, 2011 at 5:10pm.

Jack usually mowes his lawn in 7 hours. Marilyn can mow the same yard in 4 hours. How musch time would it take for them to mow the lawn together?

math/117 - smiley face, Sunday, December 4, 2011 at 5:14pm
3 hrs
math/117 - Damon, Sunday, December 4, 2011 at 5:15pm
jack mows (1/7) lawn per hour
marilyn mows (1/4) yard per hour

together they mow 1/7 + 1/4 yard per hour
= 4/28 + 7/28 = 11/28 yards per hour
so
28/11 = about 2.54 hours/yard
math/117 - Angela, Sunday, December 4, 2011 at 5:17pm
Which one is the answer? 3 or 2.54?
math/117 - Ms. Sue, Sunday, December 4, 2011 at 5:18pm
Damon's answer is correct.

Answer this Question

Related Questions

Math - Jack usually mows his lawn in three hours. Marilyn can mow the same yard ...
Algebra - Jack usually mows his lawn in 4 hours. Marilyn can mow the same yard ...
alegbra - Jack usually mows his lawn in 4 hours. Marilyn can mow the same yard ...
algebra - Jack usually mows his lawn in 6 hours. Marilyn can mow the same lawn ...
math - Jack usually mows his lawn in 4 hours. Marilyn can mow the same in 5 ...
algebra - jack usually mows his lawn in 4 hours mariltn can mow the same yard in...
algebra - 1. Find the variation constant and and an equation of variation where ...
Algebra II - Jack usually mows his lawn in 6 hours. Marilyn can mow the same ...
algebra - Jack usually mows his law in 5 hours. Marilyn can mow the same law in ...
algebra - Jack usually mows his lawn in 4hrs Marilyn can mow the same yard in ...

For Further Reading

First Name:
School Subject:
Answer: