BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

gmatprep ds

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 35
Joined: Tue Aug 24, 2010 5:16 am

gmatprep ds

by replayyyy » Sat Oct 30, 2010 6:47 am
Of the 60 animals in a certain farm, 2/3 are either pigs or cows. How many of the animals are cows?
(1) the farm has more than twice as many cows as it has pigs
(2) the farm has more than 12 pigs.
Top
Source: — Data Sufficiency |
User avatar
Community Manager
Posts: 991
Joined: Thu Sep 23, 2010 6:19 am
Location: Bangalore, India
Thanked: 146 times
Followed by:24 members

by shovan85 » Sat Oct 30, 2010 6:57 am
replayyyy wrote:Of the 60 animals in a certain farm, 2/3 are either pigs or cows. How many of the animals are cows?
(1) the farm has more than twice as many cows as it has pigs
(2) the farm has more than 12 pigs.
P + C = 60 * 2/3 = 40

1. C > 2P
let P = 10 then C = 30
let P = 11 then C = 29
.. So multiple chances. Thus NS.

2. P > 12
let P = 13 then C = 27
let P = 14 then C = 26
let P = 15 then C = 25
.. So multiple chances. Thus NS.

Combining both only P = 13 then C = 27 will satisfy.
P = 13 2P = 26 < 27 =C thus satisfied.

PS: No more other chances try with 14 it will not satisfy A :)
If the problem is Easy Respect it, if the problem is tough Attack it
Top
Legendary Member
Posts: 1337
Joined: Sat Dec 27, 2008 6:29 pm
Thanked: 127 times
Followed by:10 members

by Night reader » Sat Oct 30, 2010 11:43 am
replayyyy wrote:Of the 60 animals in a certain farm, 2/3 are either pigs or cows. How many of the animals are cows?
(1) the farm has more than twice as many cows as it has pigs
(2) the farm has more than 12 pigs.
assign properties to problem and conditions 1, 2

problem c+p = 40
condition (1) c > 2p
condition (2) p > 12


solve inequalities (1) p < c/2; (2) 12 < p; 12 < p < c/2.
p must be integer (split pigs?) p=13
solve for c, c > 2p, c > 26, c = 27

plug into problem c + p = 40, 13 + 27 = 40

with both conditions the problem can be solved.

p.s. MGMAT tips for DS
My knowledge frontiers came to evolve the GMATPill's methods - the credited study means to boost the Verbal competence. I really like their videos, especially for RC, CR and SC. You do check their study methods at https://www.gmatpill.com
Top
Post new topic Post Reply
• Page 1 of 1