Monday, July 9, 2007

Cows and the grass meadow problem

A grass meadow grew equally thick and fast. It was known tat 70 cows could eat it up in 24 days and 30 cows could eat it up in 60 days. How many cows would crop the grass in 96 days??

10 comments:

Anoop C Jacob said...

is nt the ques wrong ?? cz the 'cow * days' is xpected to be a constant here.

i assume all the cows eat equally ... :)

or is der a factor of 'grass growth' to be considered ??

Rakesh B.S said...

all cows eat equally.. the question is nt wrong..

Anoop C Jacob said...

ok.. wil give a try :)

if v change the numb of cows by 3/7 , the numb of days change by 60/24 = 2.5

dat is, 3/7 change in numb of cows produces a change of 2.5 in numb of days.

now we need to find how much the numb of cows change, when v change the numb of days by 96/60 = 1.6

2.5 --> 3/7
so 1.6 --> 0.2743 (approx)'

thrfor numb of cows is 30*0.2743 = 8cows

am i rite ?? :)

Anoop C Jacob said...

explanation of 1.6 >>> its tha factor by which the numb of days change, when v change it from 60 to 96....

2.5 >>> its the factor by which no of days change, when it changes frm 24 to 60

3/7 is the factor by which numb of cows change when we change number of days by factor 2.5

so 3/7 ---> 2.5
similarly 'x'---> 1.6, whr x is the factor by which numb of days change frm 30..

but i got a really dumb answer, as 8.1 cows... :)

i assume its 8 cows + its kid :P

lol

Rakesh B.S said...

lol

GoldenRaven said...

it may be 15 to 20 cows i think

Anoop C Jacob said...

15 to 20 cows ?? 0.o

no yaar it can be from 0-200 cows... assume any value :D

wat a weird way 2 answer :p

Prabhakar said...

it is exactly 20 cows
if it is correct tell me if u want the exact solutions.

Rakesh B.S said...

yes tats rite.. gud work prabhakar..

Krish Singhal said...

20
its easy
i had got it but just done sum calculation mistake