Let's deal with this one from the task itself. What does it mean when the given equation equals to 10?
\(\frac{x}{30} + \frac{y}{50} = 10\)
\(\frac{5x}{150} + \frac{3y}{150} = 10\) |*150
\(5x+3y=1500\)
Okay then, so now let's look at the conditions.
(1) \(x+y=500\)
Well, if we multiply this equation by 3, we will get: \(3x+3y=1500\)
And if we subtract it from the original equation, we get:
\(5x+3y=1500\)
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\(3x+3y=1500\)
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\(2x = 0\)
From the task we know that X must be non-zero. Therefore, this scenario is simply impossible!
So, Condition 1 is sufficient by itself, because we can give a definite answer 'no' to the original question.
(2) \(y–x=20\)
Unfortunately, this one is neither here nor there. We can, of course, just select such X and Y that the original question is answered as 'yes':
\(5x+3y=1500\) and \(y=20+x\)
So, \(5x + 3(20+x) = 8x + 60 = 1500\)
Then \(x = \frac{1440}{8} = 180\), and \(y=200\)
However, as far as Condition 2 goes, X can also equal to 1, and Y can equal to 21, with which we'll get nowhere near the answer above.
Therefore, Condition 2 is insufficient by itself.
The answer is A.