Data Sufficiency

OA E

E ?

jackcrystal wrote:E ?

Surprise!!!

question stem: d1/r1 > d2/r2

Statement I and II are clearly insufficient.

In statement I r1 & r2 can be same numbers or different numbers. Therefore we can have both cases, smaller & greater. Insufficient.

Similarly In statement II d1 & d2 can be same numbers or different numbers. Insufficient.

Combining I & II
let d2=1, d1=31
let r2=1, r1=31

d1/r1 > d2/r2
31/31 > 1/1
1>1--------------------NO

let d2=10, d1=40
let r2=15, r1=45

d1/r1 > d2/r2
40/10 > 45/15
4>3---------------------YES


Insufficient.

Hence E.

parallel_chase wrote:question stem: d1/r1 > d2/r2

Statement I and II are clearly insufficient.

In statement I r1 & r2 can be same numbers or different numbers. Therefore we can have both cases, smaller & greater. Insufficient.

Similarly In statement II d1 & d2 can be same numbers or different numbers. Insufficient.

Combining I & II
let d2=1, d1=31
let r2=1, r1=31

d1/r1 > d2/r2
31/31 > 1/1
1>1--------------------NO

let d2=10, d1=40
let r2=15, r1=45

d1/r1 > d2/r2
40/10 > 45/15
4>3---------------------YES


Insufficient.

Hence E.

d1/r1 > d2/r2

(d1/r1) - (d2/r2) > 0

d1r2-d2r1 / (r1r2) > 0

we know that r1r2 is positive

so it boils down to whether d1r2 > d2r1

Slightly different procedure

clearly I and II alone are insufficient

we have to find whether d1/r1 > d2/r2

given from I: d1=d2 + 30
from II: r1 = r2 + 30

d1/r1 = (d2 + 30) / (r2 + 30)
muliply and divide by r2 = (d2r2 + 30r2)/(r2*(r2+30))

d2/r2 = mutiply and divide by (r2+30)
(d2r2 + 30d2)/(r2*(r2+30))

now we have to compare the numerators of the fractions

d2r2 + 30r2 > d2r2 + 30d2
so it boils down to the comparision between
d2 and r2...................or (d1 and r1)

we dont have any info on this ......so E