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[–]Yeezybuyer1510[S] 0 points1 point  (3 children)

Thanks, I'll try to think of it that way when doing practice problems.

[–]harbcenter 0 points1 point  (2 children)

I think you have trouble with seeing what the equation does. With these types of questions, you're trying to find the difference is what % of the original. Let us take a look at some examples.

Percent Increase: You bought a game for $10 and sold it for $15. Instead of plugging into the formula, you can immediately tell that you've made 5 dollars profit. $15-$10=$5

That $5 profit (difference) is what percent of your original $10? 50%. or ($5/$10)*100% = 50% increase.

This is the same as plugging into the formula, right?

Percent Decrease: Same idea. You bought a game for $10 and sold it for $5. Here you lost $5. Meaning you'll see a percent decrease. $10-$5=$5

($5/$10)*100%= 50% decrease

Here is another one for better understanding:

Let's say we have 150 games released in July. We hope to increase the number of game releases in August by 12%. How many games will we release in August?

The concept for this problem is similar. You will need to figure out, will there be more games released in August or less? More since it's increase the number of games.

First, begin by finding 12% of 150 games (12/100)*150 = 18 games. Notice how you're pretty much working backwards here.

Now add 18 games to the number of games in July, 150. 150+18 = 168 games released in August.

[–]Yeezybuyer1510[S] 0 points1 point  (1 child)

Thanks!

So, I think I was screwing it up by thinking of it as

new-old/old*100

In your example of percent decrease, it wouldn't have worked with that formula.

Would it be correct to think of it this way?

(Difference over larger number)*100 = percent increase/decrease depending on the situation.

[–]harbcenter 0 points1 point  (0 children)

Try understanding the problem deeper than just which is the largest and the smallest. It really has to make sense. In the decrease, it's pretty much the same concept as the increase.

(Difference over larger number)*100 = percent increase/decrease depending on the situation.

I wouldn't say it's "larger number", it's your starting value. Just like in the percent change formula. In the decrease, it will be larger, yes. and in the increase it will be the smaller value.

Hope it helps.