If x = 3, y = -1, and z = 1, which of the following is (are) true?

Question

If  x = 3 ,  y = -1 , and  z = 1 , which of the following is (are) true?

I.  x+y+z=3

II.  y + 2z = 2

III.  x - 2z = 1

(A) I only 
(B) III only 
(C) I and II only 
(D) I and III only 
(E) I, II, and III

yashikaaggarwal · Answer

Given: X = 3, Y = -1 & Z = 1

Statement 1: X+Y+Z = 3
Verification : 3-1+1 = 3
=> 3 = 3 (correct)

Statement 2: Y+2Z = 2
Verification : -1+2 = 2
=> 1 ≠ 2 (incorrect)

Statement 3: X-2Z = 1
Verification: 3-2(1) = 1
=> 3 - 2 = 1
=> 1 = 1 (correct)

Only statement 1&3 are correct

Answer is D

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Nipungupta9081 · Answer

given that 
X = 3 , Y = -1 , Z = 1

statement 1 = x+y+z=3 
putting values = 3 + (-1) +1= 3
 3 = 3

Statement 2 = y+2z=2 
 -1 + 2(1) = 2
 1 = 2

Statement 3 = x−2z=1 
 3 - 2(1) = 1 
 1 = 1

Statement 1 & 3 are correct 
Answer D

Sr1994 · Answer

Substituting the values of x=3, y=-1, z=1 in each options

I) x+y+z = 3
 3-1+1 = 3
  Correct

II) y+2z=2
 -1+(2x1) = -1+2 = 1
  Wrong

III) x-2z = 1
 3-(2x1) = 3-2 = 1
  Correct

Statement 1 & 3 are correct. 
 Answer = Option D

BlueRocketAsh · Answer

I. x+y+z = 3-1+1 = 3
II. y+2z = -1+2*1 = 1
III. x−2z = 3-2*1 = 1

Answer D

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