Answer: it will take them 48 minutes.
Step-by-step explanation:
John can mow a lawn in 80 minutes. This means that the rate at which he moans the lawn per minute is 1/80
Rocky can mow the same lawn in 120 minutes. This means that the rate at which Rocky can mow the same lawn per minute is 1/120
If they work together, they would work simultaneously and their individual rates are additive. This means that their combined working rate would be
1/80 + 1/120 = 200/9600 = 1/48
Assuming it takes t hours for both of them to clean the room working together, the working rate per hour would be 1/t. Therefore,
1/48 = 1/t
t = 48 minutes
Slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept. To find b, you first need to calculate slope and see where the line intersects the y-axis.
To get m (slope), use the form y1 - y2/x1 - x2. It would look like this:
2 - 12/-1 - 4. This simplifies to:
-10/-5, which further simplifies to 2. Now, graph the points to find y....
My graph shows that the line intersects at (0, 4), so slope-intercept form would look like:
y = 2x + 4 (remember, 2 is the slope and 4 is the y-intercept)
Hope this helps.
Consider the ordering
... -2 < -1
Now consider the ordering of their absolute values:
... 1 < 2
_____
Hopefully, you see that changing the sign reflects the sequence across the origin, so that the ordering is reversed when the signs are changed.
Answer:
4.4
Step-by-step explanation:
The sum of the probabilities of all possible outcomes is 1.
As the die is loaded so that the number 4 occurs 3/10 of the time, and the other numbers occur with equal frequency, then the probability of numbers 1, 2, 3, 5, 6, 7 and 8 being rolled is 1/10.
Create a probability distribution table for X, where X is the score on the loaded 8-sided die:

Add a product row and a totals column:

(The Product is row is the product of the <u>score on the die</u> and <u>its probability</u>).
The expected value (EV) is the sum of the product of each outcome and its probability.
Therefore, the expected value (EV) of this die is 44/10 = 4.4