If Jim earns x dollars per hour, it will take him 4 hours to earn exactly enough money to purchase a particular jacket. If Tom earns y dollars per hour, it will take him exactly 5 hours to earn enough money to purchase the same jacket. How much does the jacket cost?
(1) Tom makes 20% less per hour than Jim does.
(2) x + y = $43.75
Jacket cost = 4x=5y
y/x = 4/5= 80/100 (this means Tom makes 20% less perhour than Jim does
this is duplicate information given in the question stem.
y/x = 4/5=
we have two vaiables and 1 equation.. insuffcient
2) x + y = $43.75
y/x = 4/5two equations and two unkowns.
Solve for X OR Y
Jacket cost = 4x or 5y
B is the answer.
suresh, sometimes ,GMAT exploits this very thing abt n eqns and n variables and gives us problems wherein conditions and variables may not match, but still we can solve for the variables..
i also was caught off guard.
i think that we should not go to the GMAT( other exams are ok) with preconcieved notions abt certain concepts we have learnt till now, as they will hit us using the same weapon..
You are right!! it depends what the question is looking for.
we need to be careful..
Some times question is looking e.g (find x-y-z)
and we have only two equations. Still we can find the value of "x-y-z"
2x-4y+2z= 30 -->(1)
x-3y+3z= 20 --(2)
(1)-(2) --> x-y-z=10
Suppose question says find x.
then it is not suffcient.
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