Question 327316
The sum of the digits of three-digit number is 19. The hundreds digit is three times the tens digit. The number is 198 more than the number reversed. Find the original number.
x = 100's place
y= 10's place
z= units place
..
x+y+z=19......................1
x=3y
x-3y=0........................2
100x+10y+z -198= 100z+10y+x
rearrange the terms 
100x-x+10y-10y+z-100z=198
99x-99z=198
divide by 2
x-z=2.........................3
..
Add equation 1 & 3
x+y+z+x-z=19
2x+y=19
but x=3y from equation 2
plug value of x 
2*3y+y=21
7y=21
y=3
equation 2 = x-3y=0
plug value of y
x-3*3=0
x=9
..
x+y+z=19
plug value of x&y
9+3+z=19
12+z=19
z=19-12
z=7
The number is 937