<em>Last year the chess club had 30 members. This year the club has 24 members. </em>
Last year, the chess club had 30 members. This year, the club has 24 members. Since this year had less than last year ( 30 > 24), the percent will be decreasing.
To find the percent decrease, you have to use the following formula.

Difference refers to the difference between the two numbers, 24 and 30. The difference between 24 and 30 is 6. Original refers to the original number, which is last year's amount of members in the chess group. Therefore, original = 30.
Substitute the numbers into the formula.

To convert the decimal to a fraction, multiply the decimal by 100.

The answer is the number of chess members decreased by 20%.
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Since I started off by identifying whether it was decreasing or increasing, I did the work a bit differently. When finding the difference, you would usually subtract 30 from 24, which results in -6. Above I used 6, but if you used -6, you would end up with a result of -20%, which means it decreased by 20%. They bot end up with the same result, but you don't always have to first identify whether it's decreasing or increasing.
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A). Is correct you can thank me later ;)
This is easy. He first earned $11 on Saturday and then on Sunday he earned some money. We don't know how much he earned, we just know he earned some money. Let's put the expression together. A good place to start would be the $11. Let's add eleven to the expression. And because he earned some more money, it's going to be addition. So currently, the expression stands at $11 +
And because we don't know how much money he made on Sunday, x will be the variable for how much he earned. So the expression will be
11 + x
Answer: n = 107/6
Hope I got it! You're welcome :)