Set up two equations:
1st: P (for Price family) + J (for Jenkins family) = 45 hours
2nd: 20P + 35J = 1200 liters
Rewrite the first equation as P = 45 – J
Replace P in the second equation:
20(45-J) + 35J = 1200
Simplify:
900 -20J + 35J = 1200
900 +15J = 1200
Subtract 900 from both sides:
15J = 300
Divide both sides by 15:
J = 300/15
J = 20
Jenkins used theirs for 20 hours
Price used theirs for 45-20 = 25 hours.
Answer:Robert's minimum age is 11 years.
Step-by-step explanation:
Let x represent George's age.
Let y represent Edward's age.
Let z represent Robert's age.
George is twice as old as Edward. It means that
x = 2y
Edward's age exceeds Robert's age by 4 years. It means that
z = y - 4
If the sum of the three ages is at least 56 years, it means that
x + y + z ≥ 56 - - - - - - - - - - 1
Substituting x = 2y and z = y - 4 into equation 1, it becomes
2y + y + y - 4 ≥ 56
4y - 4 ≥ 56
4y ≥ 56 + 4
y ≥ 60/4
y ≥ 15
z = y - 4 = 15 - 4
z ≥ 11
Answer:
18
Step-by-step explanation:
For this problem, we will simply plug in the values of a and b into the respective variables in the expression 3ab to "evaluate" the expression.
a = 2; b = 3
3ab
Note, that when variables like a and b are smashed with a constant, the use of multiplication is in play.
3ab = 3 * a * b
With this in mind, let's plug in the values of a and b into the expression.
3ab
= 3 (2) (3)
= 3 (6)
= 18
Hence, 3ab evaluated when a=2 and b=3 is 18.
Cheers.
Answer:
The correlation between hour of the day and the speed over the limit at which the motorist is ticketed is weak positive correlation.
Step-by-step explanation:
The correlation coefficient is a statistical degree that computes the strength of the linear relationship amid the relative movements of the two variables (i.e. dependent and independent).It ranges from -1 to +1.
The types of correlation coefficient are:
- +1 (-1) : Perfect positive (negative) correlation
- 0 to 0.30(-0.30) : Weak positive (negative) correlation
- 0.30(-0.30) to 0.70(-0.70) : Moderate positive (negative) correlation
- 0.70(-0.70) to 1 (-1) : Strong positive (negative) correlation
The correlation coefficient value between the hour of the day and the speed over the limit at which the motorist is ticketed is:
<em>r</em> = 0.12.
The value of <em>r</em> lies between:
0 < 0.12 < 0.30
Thus, the correlation between hour of the day and the speed over the limit at which the motorist is ticketed is weak positive correlation.
