I dont know if it is the quickest way...but here is my approach

stmt 1 tells nothing about y
x+y can be less than, equal to or greater than 1 depending on the value of y

insuff

stmt 2 tells nothing about the value of x
x+y can be less than, equal to or greater than 1 depending on the value of x

insuff


To check if 1 and 2 are sufficient,
you need a YES and No to eliminate C

0.70+0 < 1 ........... x+y<1 YES
but 0.879+0.121=1 ...... x+y<1 NO

Hence insuff

E

rajt wrote:Is there a quick way to solve this, instead of substituting values?

Clearly (1) or (2) is insufficient as you need x and y to solve this.

Adding up the equalities

x + y < 73/72

x+y can hence be < 1 or slightly greater than 1 (since 73/72 > 1)

Insufficient and hence E.