At a certain store, each notepad costs X dollars and each marker costs Y dollars. If $10 is enough to buy 5 notepads and 3 markers, is $10 enough to buy 4 notepads and 4 markers instead?
1. Each notepad costs less than $1
2. $10 is enough to buy 11 notepads
OA is E
Please explain your answer. Thanks,
Gmat Prep 2
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IMO E
because:
from the question
5X+3Y<=10
1)X<1
3y<=105X
3Y<=5
Y<=5/3
take numbers, X=1/2.Y=1/2
sufficient to buy 4 notepads and 4 markers
X=.9, Y=5/3 cannot buy 4 notebooks and 4 markers.
NOT SUFF
2)not sufficient , we need to know the price of markers
combined
from 2, 11X<=10
X<=10/11
same reasoning as given in A
not suff
because:
from the question
5X+3Y<=10
1)X<1
3y<=105X
3Y<=5
Y<=5/3
take numbers, X=1/2.Y=1/2
sufficient to buy 4 notepads and 4 markers
X=.9, Y=5/3 cannot buy 4 notebooks and 4 markers.
NOT SUFF
2)not sufficient , we need to know the price of markers
combined
from 2, 11X<=10
X<=10/11
same reasoning as given in A
not suff
The powers of two are bloody impolite!!