maths

Eleven Plus (11+) in Essex

Moderators: Section Moderators, Forum Moderators

Post Reply
11 Plus Mocks - Practise the real exam experience - Book Now
slush
Posts: 18
Joined: Wed Jan 11, 2012 9:36 pm

maths

Post by slush »

Hi

Would anyone be kind enough to help with this maths question.

8 people take 10 hours to do a certain job, how long would it take 20 people to do the same job?

Thanks You
Minesatea
Posts: 1234
Joined: Sat Oct 31, 2009 12:08 am

Re: maths

Post by Minesatea »

Not sure, but:

If 8 people take 10 hours each that is 80 man hours in total ie 1 man would take 80 hours to do the job.

20 people should thus take 80 / 20 = 4 hours


I think!
NOTLEY PARENTS
Posts: 178
Joined: Wed Sep 23, 2009 3:09 pm
Location: Great Notley

Re: maths

Post by NOTLEY PARENTS »

Minesatea wrote:Not sure, but:

If 8 people take 10 hours each that is 80 man hours in total ie 1 man would take 80 hours to do the job.

20 people should thus take 80 / 20 = 4 hours


I think!

I make it 4 hours too.
arsen
Posts: 25
Joined: Sat Nov 19, 2011 7:14 pm

Re: maths

Post by arsen »

It is 4 hours.

You are basically increasing the number of people by a factor of 2.5. (8x2.5=20), therefore you would be decreasing the time taken by 2.5. So 10/2.5 = 4

Hope helps!
Post Reply
11 Plus Mocks - Practise the real exam experience - Book Now