Re: 0<z<y<x
[#permalink]
01 Jul 2025, 04:00
We are given the condition: $\(0<z<y<x\)$.
Let's simplify Quantity A:
Quantity $\(\mathrm{A}=(x+10) \times y \times z\)$
$$
\(=x y z+10 y z\)
$$
Now, let's simplify Quantity B:
$$
\(\begin{aligned}
& \text { Quantity B }=x \times y \times(z+10) \\
& =x y z+10 x y
\end{aligned}\)
$$
To compare Quantity A and Quantity B, we can compare their simplified forms:
Compare $x y z+10 y z$ with $x y z+10 x y$.
We can subtract the common term $x y z$ from both quantities without changing the comparison: Compare $10 y z$ with $10 x y$.
Since 10 is a positive constant, we can divide both quantities by 10 without changing the comparison:
Compare $y z$ with $x y$.
Now, let's use the given condition $0<z<y<x$.
Since $y$ is a positive number (because $y>z>0$ ), we can divide both sides of the comparison by $y$ without changing the direction of the inequality:
Compare $z$ with $x$.
From the given condition $\(0<z<y<x\)$, we know that $z$ is less than $x$.
So, $z<x$.
Therefore, working backward:
$$
\(\begin{aligned}
& y z<x y(\text { since } y>0) \\
& 10 y z<10 x y \\
& x y z+10 y z<x y z+10 x y
\end{aligned}\)
$$
This means Quantity A is less than Quantity B.
Example to verify:
Let $z=2, y=3, x=4$. This satisfies $0<z<y<x$.
Quantity A: $\((4+10) \times 3 \times 2=14 \times 3 \times 2=14 \times 6=84\)$.
Quantity B: $\(4 \times 3 \times(2+10)=4 \times 3 \times 12=12 \times 12=144\)$.
In this example, $84<144$, so Quantity A is less than Quantity B .
The final answer is Quantity B is greater.