Percentage!!

[niketdoshi123]

The annual rent collected by a corporation from a certain building was x percent more in 1998 than in 1997 and y percent less in 1999 than in 1998. Was the annual rent collected by the corporation from the building more in 1999 than in 1997?

1) x>y
2) xy/100 <x-y

[Anurag@Gurome]

The annual rent collected by a corporation from a certain building was x percent more in 1998 than in 1997 and y percent less in 1999 than in 1998. Was the annual rent collected by the corporation from the building more in 1999 than in 1997?

1) x>y
2) xy/100 <x-y

Let the rent collected in 1997 = R
Then rent collected in 1998 = R + Rx/100 = R(1 + x/100)
Rent collected in 1999 = R(1 + x/100) - y% of R(1 + x/100) = R(1 + x/100)(1 - y/100)

Question is: Is R(1 + x/100)(1 - y/100) > R? OR Is 1 + x/100 - y/100 - xy/10000 > 1? OR Is x - y > xy/100?

(1) x > y, which does not imply whether x - y > xy/100 or not; NOT sufficient.

(2) xy/100 < x - y is exactly what the question is asking for; SUFFICIENT.

The correct answer is B.

[ronnie1985]

If 100 is the rent collected in 1997.
1998: 100+x
1999: (100+x)*(1-y/100) = 100-y+x-xy/100
Q. x-y-xy/100>0?

S1. x>y.
Cant ascertain the sign of x-y-xy/100

S2. xy/100 < x-y
Sufficient

(B) is answer