Bunuel wrote:

If x and y are both positive integers, is xy >= 250?

(1) x = 300

(2) 50 < y < 100

we are asked to find out whether xy>=250.

Important Note:

1. both x and y are positive.

2. both x and y are integers.

statement 1: x=300. if we consider the value of y in minimum range just 1 total value of xy will be greater than 250. but we have have to keep in mind that we are looking for greater that + equal. so, not sufficient.

statement 2: the range value is given here. and we don't know anything about x. so not sufficient.

so, correct answer will be E.