The answer and work is in the SS below
Short Answer: 18 minutes
Remark
The answer to this problem is less than the smallest time of the two people working together. that fact lets out C and D (38 minutes and 75 minutes). Now you have to choose 15 minutes and 18 minutes. There's a method. No guessing needed.
Givens
Let the time for Sophie = S
Let the time for Simon = M
Let the job to completion = 1
S = 45 minutes
M = 30 minutes
Step One
Convert minutes to hours.
45 minutes = 45 / 60 = 3/4 hour = 0.75 hour
30 minutes = 30 / 60 = 1/2 hour = 0.50 hour
Step Two
Set up the Equation
The formula is a form of job / hour.
Let the time = t that they both have to work
job = 1 in these problems.
1/S + 1/M = 1/t
1/0.75 + 1/0.5 = 1/t
Solve
1 ÷ 0.75 = 1.33333
1 ÷ 0.5 = 2
1.3333 + 2 = 3.33333
3.3333 = 1 / t Multlply both sides by t
3.3333*t = 1
t = 1 / 3.333333333
t = 0.3 of an hour
1 hour = 60 minutes
0.3 hours = x Cross Multiply
x = 60 * 0.3
x = 18 minutes
Answer working together it took them 18 minutes <<<<<
Answer:
C. No because Angie is not representative of the population in the algebra class
Step-by-step explanation:
I just took the test and this was correct
If you're looking for c, then the answer is 6 in. I found this answer by using a2+b2=c2 So 4 squared + 5 squared = 41. So then i found the square root of 41 which is 6.40, which rounds to 6.
Answer:
n = 21
Step-by-step explanation:
5(n-7)=2(n+14)
Distribute
5n -35 = 2n+28
Subtract 2n from each side
5n-2n -35 = 2n-2n +28
3n-35 =28
Add 35 to each side
3n-35+35 = 28+35
3n = 63
Divide by 3
3n/3 = 63/3
n =21
