SonofAnarchy wrote:
superman wrote:
This is tricky but simple
Lets the number of increase in camera be m for 1993 to 1994
==> m = 1000 * x/100 = 10x
Lets the number of increase in camera be n for 1994 to 1995
==> n = (1000 + 10x) * y/100 = (100 + x) * y/10 = 10y + xy/10
Now the cameras in 1995 = 1000 + a + b = 1000 + 10x + 10y + xy/10 = 10(100+x+y+xy/100)
Now using stmt 2 we can solve the above equation hence Stmt 2 is sufficient and hence answer is B
Note from stmt 1 we wont know values of x and y
hey,
i have a query.
we substituted the value of "xy" in the equation and are left with two unknown variable x and y.
Cant we substitute the value x=20/y also in the equation and make it a single variable equation?
From that we can find the value of x and y separately.
For anyone having the same query:
You have xy = 20
Number in 1995 = 1000 * (1 + x/100 + y/100 + xy/10000)
You can put x = 20/y and get:
Number in 1995 =
1000 * ( 1 + 20/100y + y/100 + 20/10000)What next? We still have an unknown variable y. This is not an equation that will help you solve for y. You need to find the value of the highlighted expression. Also, even if this were an equation, it is likely to give you multiple values of y.
Another thing you can note is that xy = 20 means there are multiple values of x and y possible. e.g. x = 2, y = 10 or x = 4, y = 5 etc.
The value of the expression will change depending on which pair you take since x + y is different in each case.
_________________
Karishma
Veritas Prep GMAT Instructor
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