Are you sure there isn't a typo in statement 2. This post here has an otherwise identical question:

https://www.beatthegmat.com/word-prob-t19707.html

My solution is as follows:

Rent_1987 = P
Rent_1988 = P(1 + x/100) .. x% increase from 1987
Rent_1989 = P(1 + x/100)(1 - y/100) …y% decrease from 1988

Is Rent_1989 > Rent_1987?
P(1 + x/100)(1 - y/100) > P ?
(1 + x/100)(1 - y/100) > 1 ?
1 + x/100 - y/100 -xy/10000 > 1 ?
(x - y)/100 - xy/10000 > 0 ?
(x - y)/100 > xy/10000 ?
100(x-y) > xy ? ….my question stem has been reduced to this.

Statement 1: x > y
If x = 50, y = 49, the answer to the question stem is NO.
If x = 2, y = 1, the answer to the question stem is YES.

Insufficient.

Statement 2: xy/100 < x-y (I'm assuming there is a typo in duongthang's post)

This statement directly answers the question stem as YES. Sufficient.

Choose B.

-BM-

yes, 2 is

xy/100 < x-y

you are wong

1988 rent is P(1+x)

1999 rent is P(1+x)(1-y)

because x percent is x/100

duongthang wrote:you are wong

1988 rent is P(1+x)

1999 rent is P(1+x)(1-y)

because x percent is x/100

20 percent of 50 = (20/100)*50 = 10

so the in the same way:

x percent of A = (x/100)*A

therefore x percent actually means x/100.

-BM-

so what is correct answer. IMO is E