SOLUTION: Jack usually mows his lawn in 8 hours. marilyn can mow the same yard in 6 hours. How much time would it take for them to mow the lawn together?

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Question 428211: Jack usually mows his lawn in 8 hours. marilyn can mow the same yard in 6 hours. How much time would it take for them to mow the lawn together?
Found 3 solutions by josmiceli, nerdybill, John10:
Answer by josmiceli(19441) About Me  (Show Source):
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You have to add their rates of mowing
In words:
( 1 lawn) / (Jack's time to mow it) + (1 lawn ) / (Marilyn's time to mow it) =
{1 lawn) / (Their time mowing it together)
----------------
given:
Jack's rate = 1%2F8 lawns/hour
Marilyn's rate = 1%2F6 lawns/hour
----------------
+1%2F8+%2B+1%2F6+=+1%2Ft+
Multiply both sides by 24t
+3t+%2B+4t+=+24+
+7t+=+24+
+t+=+3.43+ hrs
or, about 3 hours and 26 minutes

Answer by nerdybill(7384) About Me  (Show Source):
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Jack usually mows his lawn in 8 hours. marilyn can mow the same yard in 6 hours. How much time would it take for them to mow the lawn together?
.
Let x = time (hours) it takes for both
then
x(1/8 + 1/6) = 1
multiplying both sides by 48:
x(6 + 8) = 48
14x = 48
x = 48/14
x = 3.43 hours
or
x = 3 hours and 26 minutes

Answer by John10(297) About Me  (Show Source):
You can put this solution on YOUR website!
Jack usually mows his lawn in 8 hours. Marilyn can mow the same yard in 6 hours. How much time would it take for them to mow the lawn together?
-----------------------------------
Rate problem: Let x be the time which require for both to work together.
Jack's rate is x/8
Marilyn's rate is x/6
To complete the job together:
x/8 + x/6 = 1
Multiply both sides by LCD (24)
3x + 4x = 24
7x = 24
x = 24/7 (hours)
There you go :)