A couple dining at a restaurant receives a bill for $28.40. They wish to leave a 10% tip. Which of the following is the estimated gratuity?

from the given data, one gallon of cleaning solution requires 6 oz of ammonia. The mathematical expression of this statement can be expressed in two ways:

Or

The question requires we find the amount of ammonia needed to make 230 gallons of the solution. So, we use the second option and proceed as follows:

From the above equation, gallon of solution will cancel, and oz of ammonia is left.

Therefore, the solution will require 1380 oz of ammonia.

To form an equation from the word problem, first break the given statement into smaller statements.

First, we are given the width of the rectangle as x. We are told, the length is two times width. Mathematically, this means

Length=2*width=2*x=2x

Now, the length is 6 less than 2 times width of the rectangle. Thus, the length of rectangle in terms of width becomes:

Length =2x-6

Thus, the length of the rectangle is 2x-6.

to find the average time the athlete runs in 1 mile, find total time divided by total distance covered in the two runs.

Total distance=5+3=8 miles

Total time=25+15=40 minutes

We now know that the athlete runs 8 miles in 40 minutes, so the time the athlete will run in 1 mile will be:  

In 5 minutes, the athlete runs 1 mile.

: a ratio can be thought of a fraction of the form a/b, where b is not equal to zero. In ratio form, to means per.

Now, the class has 26 girls and 22 boys. Thus, the ratio of girls to boys becomes:

The fraction above reduces into

In ratio form, girls: boys=13:11

Thus, the ratio of girls to boys in a class of 48 students is 13 to 11.

When solving percent problems, the following words and their meaning becomes handy.

• Is means equals
• Of means multiply
• What means unknown (variable)

If we let x represent the amount of tip the couple want to leave behind, then

So, the couple will leave a tip of $2.84, which is about $3.00

The best way to visualize the student’s score for each subject is to plot them using a bar graph.

In this problem, we need to find the amount of gratuity the couple will leave. The gratuity is 16% of the total bill. Before solving the problem, the following are terms and their meaning in percent problems:

• Is means equals
• Of means multiply
• What means unknown (variable)

If we let x be the amount of gratuity, then translating the given problem into a mathematical equation becomes:

So, the value of x=9.376 and to the nearest cent, x=9.38

There, a couple will leave a gratuity of $9.38.

 we are to find the selling price of the sweater from the marked price and the discount. The marked price is given as

Discount=mark off rate*original price

Discount=15%*$78

Convert 15% into a fraction, which become 15/100=0.15. Then

Discount=0.15*$78=$11.70

The selling price of the sweater will be the original price less the discount or mark off value. Then,

Thus, the approximate selling price of the sweater is $66.

The distribution of the weights of the newborn babies is symmetric meaning the mean, mode, and median are all equal. Thus, the bell-shape curve describes this kind of distribution of weights

Correlation of two variables falls into:

Positive correlation: an increase in one variable causes another variable to increase

Negative correlation: an increase in one variable causes another one to decrease

No correlation: a change in one variable does not cause any response in another variable.

From the given choices

Option a is no correlation

Option b is a negative correlation

Option c is a negative correlation

Option d is a positive correlation

Thus, the correct statement is a.