if $33 is required, residents with budget of $10 won't be able to contribute,
so the remaining = 60 out of 80, which is more than half --> (I) in
if $48 is required, residents with budget of $10 won't be able to contribute,
so the remaining = 60 out of 80, which is more than half --> (II) in
if $55 is required, residents with budget of $10 & $50won't be able to contribute,
so the remaining = 30 out of 80, which is less than half --> (III) out
D

In order to ensure more than half the residents contribute, we need more than half of 10+20+30+20 = 80 people to contribute, so more than 40 people. The first two categories only include 30 people which isn't enough, thus we need people from the first three categories. In order to include all of those people, the contribution requirement has to be lower than $50. Only I and II are lower than 50 so we choose D.
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Before we try answering the question, let's first make sure we understand what the table is telling us.

The TOP row tells us that 10 residents are willing to pay up to $300 each.
The SECOND row tells us that 20 residents are willing to pay up to $100 each.
The THIRD row tells us that 30 residents are willing to pay up to $50 each.
The BOTTOM row tells us that 20 residents are willing to pay up to $10 each.
TOTAL number of residents = 80

Now let's examine the three statements...

Ⅰ. $33
10 residents are willing to pay $33 each.
20 residents are willing to pay $33 each.
30 residents are willing to pay $33 each.
10 + 20 + 30 = 60
So, 60 of the 80 residents are willing to pay $33 each.
In other words, more than half of the residents are willing to pay $33 each.

Ⅱ. $48
10 residents are willing to pay $48 each.
20 residents are willing to pay $48 each.
30 residents are willing to pay $48 each.
10 + 20 + 30 = 60
So, more than half of the residents are willing to pay $48 each.


Ⅲ. $55
10 residents are willing to pay $55 each.
20 residents are willing to pay $55 each.
10 + 20 = 30
So, 30 of the 80 residents are willing to pay $55 each.
In other words, LESS than half of the residents are willing to pay $55 each.

Answer: D

Cheers,
Brent
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The total number of residents is 10 + 20 + 30 + 20 = 80.

If the required contribution is $33, then 10 + 20 + 30 = 60 residents would contribute, which is more than half of the residents.

If the required contribution is $44, then again 10 + 20 + 30 = 60 residents would contribute, which is more than half of the residents.

If the required contribution is $55, then 10 + 20 = 30 residents would contribute, which is less than half the residents.

Answer: D

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