Answer:
Billy used 28 mins 30 sec to mow the lawn and Bobby used 43 mins 30 sec to now the lawn both within 72 mins
Step-by-step explanation:
let x represent Billy
let x+15 represent Bobby
x + x + 15 = 72
2x = 72 - 15
2x = 57
2x/2 = 57/2
x = 28.5 minutes = 28 minutes 30 seconds
Bobby = x + 15
= 28.5 + 15
= 43.5 minutes= 43 minutes 30 seconds
The best estimate of the population means is always the sample mean. We have the sample values, using them we can find the sample mean.
The sum of the sampled rates = 248
Sample Size = 10
Mean value of the sample = Sum of Sample Rate/Sample Size
So,
Mean of the sample = 248/10 = 24.8
Therefore, we can say that the best estimate for the population mean is 24.8
Answer:
7.5 gallons
Step-by-step explanation:
Given:
The Thomas family went for a Sunday drive.
Before they left, Mr. Thomas noticed the gas tank was ¾ full.
When they returned home the gas tank was ⅓ full.
Total capacity of the gas tank = 18 gallons
<u>Question asked:</u>
How many gallons of gas did the car use on the drive?
<u>Solu</u>tion:
Before they left, quantity of gas in the tank = 
When they returned, quantity of gas in the tank = 
Quantity of gas used on the drive = 13.5 - 6 = 7.5 gallons
Therefore, 7.5 gallons of gas used on the drive by Thomas family.
The answer would be A. When using Cramer's Rule to solve a system of equations, if the determinant of the coefficient matrix equals zero and neither numerator determinant is zero, then the system has infinite solutions. It would be hard finding this answer when we use the Cramer's Rule so instead we use the Gauss Elimination. Considering the equations:
x + y = 3 and <span>2x + 2y = 6
Determinant of the equations are </span>
<span>| 1 1 | </span>
<span>| 2 2 | = 0
</span>
the numerator determinants would be
<span>| 3 1 | . .| 1 3 | </span>
<span>| 6 2 | = | 2 6 | = 0.
Executing Gauss Elimination, any two numbers, whose sum is 3, would satisfy the given system. F</span>or instance (3, 0), <span>(2, 1) and (4, -1). Therefore, it would have infinitely many solutions. </span>
So,
Optimally, we want a number between 1 and 10 multiplied by a power of ten.
If we move the decimal place 6 places to the right, we get 6.
So we want

.
The correct option is C.