Here is a model I have made (I'm not a great artist). There are 42 circles in total, placed in 7 columns. Each column has 6 circles. This model represents 42/7 by splitting 42 into 7 parts, which are the columns, and showing that each column has 6 circles, which is the answer to 42/7.
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.
X is always dependant to Y. so that should answer the 1st one. the 2nd looks to be around 17-18. 17.5 maybe. and the 3rd is yes cause he does not go to the pool so it isnt any cost.
Answer:
b. the area to the right of 2
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X, which is also the area to the left of Z. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X, which is the area to the right of Z.
In this problem:




Percentage who did better:
P(Z > 2), which is the area to the right of 2.
Answer:
15%
Step-by-step explanation:
Find the percent of profit by dividing 45 by 300:
45/300
= 0.15
So, the percent profit was 15%