A poll of 100 tenth grade students was conducted to determine the number of students who had a dog, a cat, or a fish. the data showed that 50 students had a dog,40 students had a cat, and 20 students had a fish. further, 19 students had both a cat and a dog, 2 students had a cat and fish, 3 studetns had a dog and a fish, and 12 had only a fish. how many students had none of these pets?
2006-07-14 14:31:46 · 7 answers · asked by shahana s 1 in Science & Mathematics ➔ Mathematics
I concur. 20 students have no pets.
It turns out that 3 students have all three pets.
2006-07-14 14:56:50 · answer #1 · answered by none2perdy 4 · 0⤊ 1⤋
It depends how many students have a cat, a dog, and a fish.
Edit: actually, no it doesn't. If 20 kids have fish, 12 have ONLY fish, 3 have a dog and fish, and 2 have a cat and fish, then 3 have a cat, a dog, and a fish. So with that in mind, add up the number of students with a dog, a cat, or a fish; then subtract all of the overlap. This leaves you with the number of kids with any combination of pets. I think....
Edit 2: I could be wrong, but the answer I get is 17 students without any pets. (50 + 40 + 20) - 19 - 3 - 2 - 3 = 83 with pets, leaving 17 of 100 without.
2006-07-14 14:36:02 · answer #2 · answered by agentdenim 3 · 0⤊ 0⤋
20
Use Venn Diagram to solve it.
Do not worry about the 100 number until you have the diagram solved.
Add all numbers on the diagram and the result subtract from 100.
You need to subtract twice the 3 students that have dog, fish, and cat if you are doing this way.
19 students had both a cat and a dog means that they had a cat and a dog and not a fish or the problem can not be solved.
agentdenim - you are right but draw the diagram and you will see that the 3 students that have dog, fish, and cat need to be subtracted twice. That gives 20 students with no pet.
2006-07-14 14:39:25 · answer #3 · answered by Found It 1 · 0⤊ 0⤋
This type of a sum can easily be solved by Venn-diagrams=
we know total students=100
students owning dog-50
" " cat-40
" " fish-20+12=32
" " dog &cat=19
" " fish & cat=2
" " dog & fish=3
so, dogs= 50-19-3=28
so,cats=40-19-2=19
so,fish=32-3-2=27
so, dogs cats and fish together=(28+19+27)-19+3+2
" , " " " " " = 74+24=98
there fore, 100-98=2
So 2 students didnot have a pet.
2006-07-14 17:30:33 · answer #4 · answered by soubhik s 1 · 0⤊ 0⤋
How my dad and I figured it out was by using Venn diagrams. Assuming that the statement "2 students had a cat and fish" means they had ONLY a cat and a fish, then 80 students would have pets, and 20 students would not have pets out of the 100.
2006-07-14 14:52:03 · answer #5 · answered by Bookworm 1 · 0⤊ 0⤋
your question is wrong and no answer can find for it
12 student have just 1 fish
2 student have 2 fish and 2 dog
3 student have 3 fish and 3 dog
so it is going to be 17 student with 12 fish totaly , so how can you say 20 student have fish
2006-07-14 14:41:15 · answer #6 · answered by Anonymous · 0⤊ 0⤋
the answer is 0.
2006-07-14 15:30:25 · answer #7 · answered by Jordan G 1 · 0⤊ 0⤋