1.) 12 Cups of Coffee: 98% Water: x= actual coffee

12 * .98 is the same as .98 * 12, but I have trouble recognizing that. Commutative, either way.

That is wrong because it is really the 2% we are looking for- .02 * 12 = x x=0.24

2.) 90mL of Alcohol: 12% alcohol: total capacity in bottle (aka x -what we are looking for.)

.12 * x = 90

How do we solve this: divide .12/.12 (which now become .12 even though it looks like twelves its not twelve I swear its point one two.

.12/.12 * x= 90/.12 = 750 mL

3.) More Formulas: Quantit of Substance= Amount of Solution *Percent See here: Q=Ar

Distance= rate * time See: d=r(t) Ex: 13 miles is our distance, rate is 2 miles because your getting pushed back by 3 miles, and time is unknown (x), so 13=2(x) How do we solve this: Get rid of x, so we divide. 13/2 = 2x/2 that right there cancels and we are left with 13/2 which is 6.5 hours. Final answer x= 6.5 hours.

4.) Number * Variable = Number like this: ax=b

Dealing with percents: Of means Multiply, Is means Equal. Seen like this, Of: Multiplication, is: Equals

Percent * Base Amount = Amount Change

- 289.99 * .06 = $17.40 that’s how much tax, now 289.99 + 17.40= 307. 39 that was the total price.
- Here’s another way: (1 + 0.6) * 289.99 = 307.39 that was: (1+percent) * Base Amount = New Amount

A.) 70% of 330- Equation: 330 * .7 = x Multiply x=231

B.) What is 27% of 14- Equation: .15/.15 * x = 24/.15 Divide 15/24= 160 Move the decimal over

C.) 15 % of what number is 24- Equation x * .27/.27 = 14/.27 Divide 27/140 = .51815 repeating Move the decimal x= 51.851%

D.) 30% of 90- Equation: Multiply .3 * 90= 27 then Subtract 90 – 27 = 63.

Another way: (100%-30%) * 90 70%* 90 .7 * 90 = 63

I = Prt (Interest = Principle * rate * time)

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