Data Sufficiency

IS x+y <1

x<8/9

y<1/8

Can some one answer

E.

can u explain

Imagine x=8/9=64/72 and y=1/8=9/72.

In this case, x+y=73/72.

However, we know that x is strictly less than 8/9 and y is strictly less than 1/8. That's fine. Set it so that x+y=72.5/72. Because in the case of equality, the sum equals 73/72, you know that there is a case which satisfies both "less than" criteria which sums to 72.5/72 (it's not worth it to solve out the fraction, you just need to realize that one exists... i.e., if x=7.999999/9 and y=.99999999/8 ). This sum is greater than one.

On the other hand, if x=y=0, the sum is definitely less than 1.

Thanks:)