If x < y and y < 10, what is the greatest possible integer value of x + y?

[BTGmoderatorDC]

If x < y and y < 10, what is the greatest possible integer value of x + y?

A. 16
B. 17
C. 18
D. 19
E. 20


OA D

Source: Veritas Prep

[regor60]

Easy to make the assumption that since the question is seeking an integer value that the individual values must also be integers, but that is not stated as a limitation.

So the goal is to maximize both X and Y to maximize their sum.

Clearly each can be >9 and every amount below 10 that Y is must be added to 9 to create X and to create an integer result, as follows:

a=10-Y and Y=10-a
X=9+a

So X+Y = 10-a+9+a = 19,D