SOLUTION: Michael can mow 2/5 of his yard in one hour. How many hours would it take for Michael to mow 9/10 of his yard? i do not under stand this question

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Michael can mow 2/5 of his yard in one hour. How many hours would it take for Michael to mow 9/10 of his yard? i do not under stand this question      Log On


   



Question 998161: Michael can mow 2/5 of his yard in one hour.
How many hours would it take for Michael to mow 9/10 of his yard? i do not under stand this question

Found 4 solutions by CubeyThePenguin, ikleyn, greenestamps, josgarithmetic:
Answer by CubeyThePenguin(3113) About Me  (Show Source):
You can put this solution on YOUR website!
2/5 of his yard in one hour --> can mow the entire yard in 5/2 hours

%285%2F2%29%2F%289%2F10%29+=+25%2F9 of the lawn mowed in 9/10 hours

Answer by ikleyn(52824) About Me  (Show Source):
You can put this solution on YOUR website!
.

            What is written in the post by  @CubeyThePenguin  is nonsense.

            A correct solution and the correct answer is  THIS


The time to complete the job is the job divided by the rate.


The job is  9%2F10 of the entire yard;  the rate is  2%2F5  of the yard per hour; hence the time is

    %28%289%2F10%29%29%2F%28%282%2F5%29%29 = %289%2A5%29%2F%2810%2A2%29 = 45%2F20 = 135%2F60 = 135 minutes = 2 hours and 15 minutes.    ANSWER

Solved.



Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


After two wrong answers, you deserve a correct one....

2/5 of the lawn is 4/10 of the lawn.

9/10 of the lawn is 9/4 as much as 4/10 of the lawn.

4/10 of the lawn in 1 hour means 9/10 of the lawn is 9/4 times 1 hour, or 9/4 hours.

OR....

2/5 in one hour --> 5/2 hours to mow the whole lawn

5/2 hours to mow the whole lawn --> (9/10)(5/2) = 9/4 hours to mow 9/10 of the lawn

OR....

2/5 = 4/10 of the lawn in 1 hour --> 1/10 of the lawn in 1/4 hour, or 15 minutes.

1/10 of the lawn in 1/4 hour or 15 minutes --> 9/10 of the lawn in 9/4 hours or 15(9)=135 minutes

ANSWER: 9/4 hours, or 2.25 hours, or 135 minutes, or 2 hours 15 minutes.


Answer by josgarithmetic(39621) About Me  (Show Source):