An Opera house has 200 seats of two kinds: Box seats and Stall seats.

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What we know
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Let b = the quantity of box seats available in the house
Let s = the quantity of stall seats available in the house

Now let b* = the actual quantity of box seats sold
And let s* = the actual quantity of stall seats sold

We know two things right away:
(1) We know b + s = 200
(2) We know 355b + 150s = 36,150

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What does A tell us?
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A says >85% of the seats of each type are sold.

So b* > 0.85 * b and s* > 0.85 * s

Let's take our statement from (2) above

355b + 150s = 36,150
0.85 * (355b + 150s) = 0.85 * 36,150
355(0.85)b + 150(0.85)s = 0.85 * 36,150

We know b* > 0.85b and s* > 0.85s, so we can say:

355b* + 150s* > 0.85*36,150 > 30,000

So A is sufficient!

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What does B tell us?
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The number of stall seats sold is approximately 5x the number of box seats. (What does approximately mean? No idea.)

But we can put it like this:

s* ~= 5b*

We can plug these in to estimate the actual sales with the following expression:

~355b* + 150(5b*)
~1,105b*

Now we know 355b + 150s = 36,150, which is a firm upper bound for the above.

So 1,105b* < 36,150 (roughly)
So b* < 33 (roughly)

Well, this isn't actually very useful information on its own.

Suppose b* = 1. Then the sales are roughly $1,105 -- this is far below $30,000.
But b* could also be about 30, in which case the sales are roughly $33,150, which is above $30,000

So part B doesn't actually tell us anything useful

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As a result, the answer is A