Each of the numbers w, x, y, and z is equal to either 0 or 1. What is the value of w + x + y + z ?
STATEMENT (1)- \(\frac{w}{2}\)+ \(\frac{x}{4}\) + \(\frac{y}{8}\)+ \(\frac{z}{16}\) = \(\frac{11}{16}\)
8w+4x+2y+z = 11
given - w, x, y, and z is equal to either 0 or 1
now, w cant be = 0
if w = 0 then 4x+2y+z cant be = 11 (cause maximum value of 4x+2y+z = 7)
so, w = 1
x cant be = 1 cause 8w+4x will be greater than 11 which is not possible
so, x = 0
now for 8w+4x+2y+z to be = 11 only possible value of y and z = 1
w = 1, x = 0, y = 1, z = 1
value of w + x + y + z = 3
SUFFICIENT
STATEMENT (2) - \(\frac{w}{3}\) + \(\frac{x}{9}\) + \(\frac{y}{27}\) + \(\frac{z}{81}\) = \(\frac{31}{81}\)
27w + 9x + 3y + z = 31
given - w, x, y, and z is equal to either 0 or 1
now, w cant be = 0
if w = 0 then 9x+3y+z cant be = 31 (cause maximum value of 9x+3y+z = 13 if x = 1 y =1 z = 1 )
so, w = 1
x cant be = 1 cause 27w+9x will be greater than 31 which is not possible
so, x = 0
now for 27w+9x+3y+z to be = 31 only possible value of y and z = 1
w = 1, x = 0, y = 1, z = 1
value of w + x + y + z = 3
SUFFICIENT
D is the answer