venn diagram confused

zee-f · 2012-09-22 04:44:00

This thing is like confusing impossible to solve help please

A mother rabbit has twelve baby bunnies. Six of the babies are brown, eight of the babies have floppy ears, and six of the babies have long hair. All of the bunnies have at least one of these three traits. Two baby bunnies are brown and have floppy ears. Four baby bunnies are brown with long hair. Two baby bunnies have floppy ears and long hair but are not brown. One baby bunny is brown with long hair and floppy ears. Four baby bunnies are white with short hair and floppy ears. How many bunnies are brown with long hair, but don't have floppy ears? (Hint: If a baby bunny is brown with floppy ears, it may or may not have long hair--leave the option open until you are sure!)

Bob · 2012-09-22 06:56:18

hi zee-f

Draw three circles for brown hair, floppy ears and long hair.

The space has 8 regions: "none of these features"; "brown without floppy ears and without long hair"; "brown with floppy ears but without long hair" and so on. I'll leave as an exercise working out the other regions.

Put a number in a single region only if you know it. If a given piece of information covers more than one of the eight don't write it in any region as that will confuse the arithmetic. But you could, for instance, colour the border of all the affected regions and write a key at the side for the total in those regions.

eg. 'Two baby bunnies have floppy ears and long hair but are not brown.' refers to a single region so you can write inside '2'.

But 'Two baby bunnies are brown and have floppy ears' is not the information for a single region as it consists of 'brown with floppy ears and long hair' + 'brown with floppy ears but not long hair'

There is enough information to work out all 8 regions. If you cannot do it with arithmetic alone try calling the number in one region 'x' and make an equation to solve for x.

Hope that helps.

If not, post back and I'll start you off with the diagram.

LATER EDIT: Just tried it. No algebra required; just fill in the three regions where you know all three properties (brown/white; floppy/not floppy; long/short). Then use the multi-region info to calculate the rest.

Bob

anonimnystefy · 2012-09-22 08:41:16

Hi Bob

I am very surprised that your post did not include a diagram!

zee-f · 2012-09-22 09:57:13

Hey,

I am still kinda confused this is how I started (in the image below)

Don't i subtract two from brown and floppy ears when I want to add the next info?

Thanks all so so much for giving me part of your time

Bob · 2012-09-22 10:27:17

hi zee-f

Let me try to explain a different way.

Let B stand for Brown, F for Floppy and L stand for Long.

Also notB means not Brown etc.

Then the 8 regions are

B and F and L
B and F and notL
B and notF and L
B and notF and notL
notB and F and L
notB and F and notL
notB and notF and L
notB and notF and notL

hi Stefy: Sorry I disappointed you with no diagram. You'll be pleased to see I have made one now.

to zee-f: the diagram shows the 8 regions.

You can put in 3 numbers for the regions (plus the outside)

ie. Enter numbers for
B and F and L
notB and F and notL
notB and F and L
notB and notF and notL

After that you can work out the correct numbers for the remaining regions by using the other information.

Bob

zee-f · 2012-09-22 10:54:35

This is what I did or at least try to do with bob bundy's gram is that correct?

But like when I know I have 6 brown and 6 long hair and they give the info that says Four baby bunnies are brown with long hair do I subtract 4 from both the 6 brown and 6 long hair?

Bob · 2012-09-22 11:22:24

hi zee-f

Some of your diagarm is correct :)but some is not .

B and F and L = 1 tick
not B and F and L = 2 tick
not B and F and not L = 8 not correct

You are told

Four baby bunnies are white with short hair and floppy ears.

If they are white then they are notB and if they have short hair then they are notL

So the region notB and F and not L should be 4 not 8.

Also you are told

All of the bunnies have at least one of these three traits

So notB and notF and notL is zero.

Try again with these corrected numbers.

Bob

zee-f · 2012-09-22 12:13:45

OMG I finally yay! thank you so so so soooooooooooo much the diagram is completed as the following

How many bunnies are brown with long hair, but don't have floppy ears?

3 bunnies are brown with long hair, but don't have floppy ears

Bob · 2012-09-22 19:13:47

Excellent! You've got it.

The same diagram (maybe change the letters to suit the problem) should work for any 3 trait Venn diagram question.

Bob

Math Is Fun Forum

#1 2012-09-22 04:44:00

venn diagram confused

#2 2012-09-22 06:56:18

Re: venn diagram confused

#3 2012-09-22 08:41:16

Re: venn diagram confused

#4 2012-09-22 09:57:13

Re: venn diagram confused

#5 2012-09-22 10:27:17

Re: venn diagram confused

#6 2012-09-22 10:54:35

Re: venn diagram confused

#7 2012-09-22 11:22:24

Re: venn diagram confused

#8 2012-09-22 12:13:45

Re: venn diagram confused

#9 2012-09-22 19:13:47

Re: venn diagram confused

Board footer