Data Sufficiency

Hi,

I thought the answer is B) but correct answer is E). Please explain

Are the numbers k/4,z/3 and r/2 in increasing order?
(1) 3 < z < 4
(2) r < z < k

My logic is.....

k/4<z/3<r/2

or after multiplying by 12 ---> 3k < 4z < 6r and we have r<z<k

pick numbers
r=1, z=2, k=3 so we have 9 < 8 < 6 not true

pick numbers
r=1, z=8, k=12 so we have 36 < 32 < 6 not true

pick numbers
r=-1, z=0, k=12 so we have 36 < 0 < -6 not true

So we know that this is never true

Please let me know whats wrong with my logic here

gviren wrote:Hi,

I thought the answer is B) but correct answer is E). Please explain

Are the numbers k/4,z/3 and r/2 in increasing order?
(1) 3 < z < 4
(2) r < z < k

For (2), one simple test is k=4, z=3 and r=2

r<z<k but k/4, z/3 and r/2 are all equal.

Just vary r from 2 to 2.2 and you'll see the condition is no longer true.
Hence insufficient.

or just put r as a negative number. the condition doesn't maintain its clause

Consider the situation when r < z < k where r = 2, z=3 and k = 4; here r/2 = z/3 = k/4 = 1

Hence insufficient since you'll get varying answers