Braingle: 'Digging Rabbits' Brain Teaser

Digging Rabbits

Math brain teasers require computations to solve.

Puzzle ID:	#7759
Fun:	(2.69)
Difficulty:	(1.98)
Category:	Math
Submitted By:	hprulz

If one small rabbit can dig a warren in nine hours, a medium rabbit can dig a warren in 6 hours and a large rabbit can dig a warren in four and a half hours, how long will it take one small, one medium and one large rabbit to dig a warren if they all work together?

Show Answer

What Next?

See another brain teaser just like this one...

Or, just get a random brain teaser

If you become a registered user you can vote on this brain teaser, keep track of
which ones you have seen, and even make your own.

Comments

tissue Oct 04, 2002	Isn't this basically if man and a half can dig a hole and a half...
stargirl Oct 05, 2002	well, that is sorta a good one
hairomero Oct 07, 2002	What i did was...trial and error..my first instint was 2 hours so i took 2 and divided by # of hours each took. ex. small takes 9 hours so its 2/9..then i took the percentage of that and did that for the other two. It came up to 99% when i added the 3 together so i guess thats correct.
waffle Feb 27, 2005	This was really easy. You just have to add some fractions to figure out how much of a warren they can dig in one hour.
waffle Feb 27, 2005	This was really easy. You just have to add some fractions to figure out how much of a warren they can dig in one hour.
Jimbo Jun 04, 2012	An easy way to think about it (9, 6 and 4.5 divide into 1 is to imagine that a warren contains 18 cubic metres of dirt. Rabbit A digs 2 cum/hr, Rabbit B digs 3 cum/hr and rabbit C digs 4 cum/hr. Altogether they dig 9 cum/hr so it takes 2 hours. Good Teaser.