Data Sufficiency

is it E?

5x+3y<=10 (<= less than or equal to 10)
Is 4x+4y<=10?

1) x<1
2) 11x<=10 ------> x<=0,909...

The price of each notepad ranges from $0.01 to $0.91 (or $0.99 in the first statement). If $0.01, then $10 is enough to buy 4 markers. If $0.99, it's not enough.

Answer is E. Thanks. I wrote down the equations pretty much as you did, but for some reason changed my answer to D. Should go with knowledge not gut feeling.

Can someone please explain how you know that 0.99 is not enough to buy 4 markers?

Isn't the answer E because we don't know anything about Y here??

I picked D first because instead of reading question that $10 is enough to buy 5 notepads and 3 markers I read the question as “Cost of 5 notepads and 3 markers is $10” which is wrong.
ans is “E”

5x+3y<=10
To prove:- 4x+4y<=10
Or x+ y <=2.5

N<1
Let n=0.9
Therefore, M<=1.8
Insuff

11N=10
M<=1.7
Insuff
Combined 1 and 2 also Insuff

AleksandrM wrote:Answer is E. Thanks. I wrote down the equations pretty much as you did, but for some reason changed my answer to D. Should go with knowledge not gut feeling.

Yeah gut feeling is dangerous. At first glance I too had thought the answer to be D and left it at that, it is only after the actual answer was given that I realized my mistake.