False.
In a random sample each member of the group has the same chances to be choosen. A representative sample replicates the characteristcs that you want of the group. Many times you need to make the sampling not random to pick a sample that represents or replicates the group.
Your two equations are at the top, in the box is what each variable represents. Below the box is total liters of the 15%, which is going to equal the total liters for 10% plus the total liters for 25%. Make your percentages into decimals. There’s a total of 30 liters so, x+y needs to equal 30. Isolate a variable, I chose y, you can do either or (isolating x would be more math). Y is going to equal 30-x, substitute that for the Y in the second equation, then you need to distribute 0.25 into 30-x. Then it’s simple math, subtract 7.50 from both sides, add like gets, divide both sides by -0.15, making x=20.
Answer:
49
Step-by-step explanation:
y = 7^2
= 49
1440 divided by 120 = 12 pen stands
hope it helps:))