Question

If it is known that $x+y=10$ and that $x=z$, then $z+y=$

• A. $20$
• B. $30$
• C. $10$
• D. $0$

Answer 1

The correct option is C $10$

Let $x+y=10$ __(i) and $z+y=10$ ___ (ii)
Subtracting $x$ from both sides of the equation we get,
$x+y-x=10-z$[When equals are subtracted from equals,remainder are equal]
$⟹y=10-z$[adding z on both sides of the equation]
$⟹y+z=10$