All Algebra 1 Resources
Example Questions
Example Question #1 : Proportions
The probability of an event is 3/11. Find the chance the event will not occur.
3/11
8/3
11/3
8/11
3/8
8/11
If the chance an event will happen is 3/11, that means there are 8 instances where the even would not occur out of every 11, giving us 8/11.
3 chances out of 11 = event
11 – 3 = 8
8 chances out of 11 = no event
Example Question #2 : Proportions
Solve for :
Cross multiply:
Solve for :
Example Question #3 : Proportions
Solve for in the following proportion statement:
Use cross-multiplication to set up the following equation:
Rewrite with improper fractions and solve:
So the correct choice is .
Example Question #3 : Proportions
Example Question #2 : Proportions
If Max drives 10 miles in 24 minutes, how many minutes will it take for him to drive 25 miles?
Set up a proportion, with miles driven on top and the time (in minutes) on the bottom:
Then, cross multiply:
, or
Finally, dividing both sides by 10 gives:
minutes.
Example Question #2 : Proportions
A recipe for making 24 cookies calls for 6 cups of sugar. How many cups of sugar would be needed to make 16 cookies?
To solve the equation, you can set up a proportion with as the cups of sugar needed for making cookies. In this case, we know that it takes 6 cups of sugar to make 24 cookies, so we can set up the proportion as . Since we know that we need to make 16 cookies, we can substitute 16 for , . Cross multiply the fractions to get . Now, solve for to get a solution of 4.
Example Question #3 : Proportions
Example Question #4 : Proportions
To make 36 cookies, a recipe calls for 5 ounces of chocolate chips. How many ounces of chocolate chips would you need to make 900 cookies?
None of the other answers
To figure out how many ounces of chocolate chips are needed to make 900 cookies, you simply need to set up a proportion. In this case, we know that 5 ounces of chocolate chips are needed to make 36 cookies, and we are trying to make a total of 900 cookies. Therefore, you can set up the proportion as
where is the ounces of chocolate chips needed to make 900 cookies.
For this proportion, solving for would give you a result of 125 ounces of chocolate chips.
Example Question #3 : Proportions
If , what is the value of ?
,
,
,
,
Proportions are useful for solving many types of problems, but here our equation itself is a proportion.
To solve, we cross-multiply: the numerator of one side times the denominator of the other and vice versa. We are left with
or
A simple FOIL gives us
so our solutions are and .
Example Question #5 : Proportions
If , what is the value of ?
To solve this equation, we need to set up a simple proportion. Since the variables and are already in use, let's call the quantity that we are solving for . From the given information, we know we can use the proportion . Cross-multiplication yields . Dividing by the common term of and simplifying the right side gives us , so our solution must be .
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