KVPY2015MathematicsBasics of Mathematics
Let x, y, z be positive reals. Which of the following implies x=y=z ?
Options
- Ax³+y³+z³=3 x y z
- Bx³+y² z+y z²=3 x y z
- Cx³+y² z+z² x=3 x y z
- D(x+y+z)³=27 x y z
Correct answer
B. x³+y² z+y z²=3 x y z
Step-by-step solution
For option (3) if x=z=1 and y=2 then option (3) is right. So by option (3) we can't say x=y=z . Remaining options implies x=y=z