Answer:
C. 18
Explanation:
Let's say the first number is x so the second will be x+1 and the third will be x+2
x+ x+1+x+2=51
3x+3=51
3x=51-3
3x=48
3x/3=48/3
X=16 this is the first number
The second number will be x+1=16+1=17
The third number will be x+2=16+2=18
So the greatest number will be 18