If x, y, and z are positive integers and 3x = 4y = 7z, then the least possible value of x - y + z is  Options
A) 33	B) 40	C) 49	D) 19	E) 61
x - y + z = - 3x/4 + x + 3x/7   = (- 21 + 28 + 12 )x/28 = 19x/28   19 is not divisible by 28(it's a prime #), so for least value, x = 28   Answer - 19
<result>D</result>
If x, y, and z are positive integers and 3x = 4y = 7z, then the least possible value of x - y + z is