To answer this problem, one way is to use the calculator and add directly the two numbers and get the average between the two. The answer is 25/77. We can also get this number by getting the LCM of the denominators which is 77. 2/7 is equal to 22/77 while 4/11 is equal to 28/77. 0.5*(22 +28) is equal to 25. Hence the answer is 25/77.
Answer:
4:1 (I think)
Step-by-step explanation:
Let's write some equations first:
For both prices increasing by 20:

then we can use cross multiplication
2x+40=5y+100
For both prices decreasing by 5:

same here:
5y-25=x-5
Using substitution for 5y, we get: 5y=x+20
2x+40=5y+100
2x+40=x+20+100
x=80
plugging this in to the second equation:
5y-25=x-5
5y-25=80-5
5y-25=75
5y=100
y=20
therefore we get x:y=80:20
4:1
Answer:
5.04
Step-by-step explanation:
Answer:
P(a junior or a senior)=1
Step-by-step explanation:
The formula of the probability is given by:

Where P(A) is the probability of occurring an event A, n(A) is the number of favorable outcomes and N is the total number of outcomes.
In this case, N is the total number of the students of statistics class.
N=18+10=28
The probability of the union of two mutually exclusive events is given by:

Therefore:
P(a junior or a senior) =P(a junior)+P(a senior)
Because a student is a junior or a senior, not both.
n(a junior)=18
n(a senior)=10
P(a junior)=18/28
P(a senior) = 10/28
P(a junior or a senior) = 18/28 + 10/28
Solving the sum of the fractions:
P(a junior or a senior) = 28/28 = 1