Answer:
125
Step-by-step explanation:
To find the expected number of black marbles, take the probability of getting a black marble times the number of marbles drawn
P(black) * 200
5/8 *200
125
We should expect 125 black marbles
Answer:
$39
Step-by-step explanation:
$62 = t - $22 + $60 - $15
t = $39
Answer: 0.5143
Step-by-step explanation:
Probability of students who are over 21 years old = 30% = 0.3
Probability of students who are under 21 years old = 100% - 30% = 70% = 0.7
Probability of drinking alcohol for over 21 = 80% = 0.8
Probability of not drinking alcohol for over 21 = 100%- 80% = 20% = 0.2
Let the probability of the students who are not over 21, that drink alcohol be p.
Total probability of a college student drinking alcohol = (0.3 × 0.8) + (0.7 × p)
0.6 = (0.3 × 0.8) + (0.7 × p)
0.6 = 0.24 + 0.7p
0.7p = 0.6 - 0.24
0.7p = 0.36
p = 0.36/0.7
p = 0.5143
The probability of the students who are not over 21, that drink alcohol is 0.5143.
Because it is much easier to identify the place values when multiplying numbers. You can immediately sight the numbers to be multipied.
An example
10
x 5
___
0
Then
5 -0= 50
Use order of operations or ----> PEMDAS
(9.2-4.9÷7) +36.4
first divide -4.9 by 7 in the parenthesis.
9.2-0.7+34.6
now add -0.7 and 34.6
9.2+33.9
now add these numbers together and your answer is.... 43.1
