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.

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