If x < 10 and 2x - 3y = 8 which of the following must be true?

Question: If x < 10 and 2x - 3y = 8 which of the following must be true?

Solution:
Given that,
x < 10 and 2x - 3y = 8
We need to determine which statement must be true from the options.

Now,
2x - 3y = 8
⇒ 3y = 2x - 8
⇒ y = (2x - 8)/3
Since x < 10, substitute into the expression for y,
⇒ y < {(2 × 10) - 8}/3
⇒ y < (20 - 8)/3
⇒ y < 12/3
∴ y = 4
∴ if x < 10, then y < 4.

So the statement that must be true is y < 4.