Math question probability : PS Archive
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# Math question probability

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Intern
Joined: 18 Dec 2009
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28 Dec 2009, 10:53
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Hello,

Here is the problem:

"At a certain pet stores, 1/3 of the pets are dog, 1/5 are dogs, how many of the pets are dog

1) There are 30 birds at the pet shop
2) There are 20 more dogs than birds at the pet shop

The answer was: each statement alone is sufficient

1) ==> Total number of pets = 30 birds x 5 = 150 pets
Number total of dogs = 150 pets/3 = 50 dogs

2) N_dogs = N_birds + 20
=> How this statement is sufficient alone?

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28 Dec 2009, 11:09
[quote="nailgmattoefl"]Hello,

Here is the problem:

"At a certain pet stores, 1/3 of the pets are dog, 1/5 are dogs, how many of the pets are dog

1) There are 30 birds at the pet shop
2) There are 20 more dogs than birds at the pet shop

The answer was: each statement alone is sufficient

1) ==> Total number of pets = 30 birds x 5 = 150 pets
Number total of dogs = 150 pets/3 = 50 dogs

2) N_dogs = N_birds + 20
=> How this statement is sufficient alone?

i guess frm ur SI, 1/5 are birds.....
for SII, let toyal pet be x.. so birds=x/5 and dogs =x/3..... SII gives the diff as 20...
x/3-x/5=20.... x=20*15/2=150... dogs are 150/3=50 SUFF
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Intern
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29 Dec 2009, 06:09
"1/3 of the pets are dog, 1/5 are dogs"

This statement does not make sence to me.
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29 Dec 2009, 06:46
nailgmattoefl wrote:
Hello,
Here is the problem:
"At a certain pet stores, 1/3 of the pets are dog, 1/5 are [strike]dogs[/strike] birds, how many of the pets are dog
1) There are 30 birds at the pet shop
2) There are 20 more dogs than birds at the pet shop
The answer was: each statement alone is sufficient
1) ==> Total number of pets = 30 birds x 5 = 150 pets
Number total of dogs = 150 pets/3 = 50 dogs
2) N_dogs = N_birds + 20
=> How this statement is sufficient alone?

i think its 1/5 bird well in that case
eqn for s2) is N_dogs=N_birds+20
N_doga=1/3 Pets
N_birds=1/5 pets
--->1/3 pets =1/5 pets+20----> solving pets =150

rest u knw hence its suff

and kindly recheck the q and edit it
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Re: Math question probability   [#permalink] 29 Dec 2009, 06:46
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