The answer is A: A uniform probability model is a good model to represent probabilities related to the numbers generated in Pedro's experiment.
and B: It is likely that the spinner is fair.
I can’t answer this question because I can’t see the model
Answer:
There is a 3/20 chance that a red plastic marble will be taken out on random.
Step-by-step explanation:
This is because there are 14 yellow marbles, and 6 red marbles. Along with this, half of the red marbles are made out of plastic. This leaves 3/6 of the red marbles made out of plastic. When combined with the yellow marbles, you'll add 14 to the denominator, since there are 14 yellow marbles. (Red + Yellow = Total Number Of Marbles) This leads to a total count of 3 marbles of the 20 total marbles, being red and made out of plastic.
Answer:
31
Step-by-step explanation:
210 ft ÷ 7 ft = 30
There are 30 7-ft lengths of fence.
Think of putting a post at the end of each 7-ft length. That means you need 30 posts. Now you must add 1 post for the beginning.
Answer: 31
Answer: the speed of the boat on the lake is 9 mph
Step-by-step explanation:
Let x represent the speed of the boat on the lake or in still water.
The speed of the current in a river is 6 mph. This means that if the boat goes upstream against the speed of the current, its total speed would be (x - 6)mph. If the boat goes downstream against the speed of the current, its total speed would be (x + 6)mph.
Time = distance/ speed
Every day, his route takes him 22.5 miles each way against the current and back to his dock, and he needs to make this trip in a total of 9 hours. This means that the time taken to travel upstream is
22.5/(x - 6). The time taken to travel downstream is
22.5/(x + 6)
Since the total time is 9 hours, it means that
22.5/(x - 6) = 22.5/(x + 6)
Cross multiplying, it becomes
22.5(x + 6) + 22.5(x - 6) = 9
Multiplying through by (x + 6)(x - 6), it becomes
22.5(x - 6) + 22.5(x + 6) = 9[(x + 6)(x - 6)]
22.5x - 135 + 22.5x + 135 = 9(x² - 6x + 6x - 36)
22.5x + 22.5x = 9x² - 324
9x² - 45x - 324 = 0
Dividing through by 9, it becomes
x² - 5x - 36 = 0
x² + 4x - 9x - 36 = 0
x(x + 4) - 9(x + 4) = 0
x - 9 = 0 or x + 4 = 0
x = 9 or x = - 4
Since the speed cannot be negative, then x = 9
