Your answer is 9x-8.
3x+4, x-10, 5x-2. If you combine the x's you get 9x. You can combine the numbers however you'd like. I chose to combine +4 and -2. That's 2. 2-10 = -8. Therefore your answer is 9x-8.
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:
the correct anser is B
Step-by-step explanation:
Calculate the area of the shape on all the corners
Answer:
Step-by-step explanation:
This is a special die. Its six sides bear the numbers {9, 10, 11, 12, 13, 14}.
There are three possibilities for getting a multiple of two: {10, 12, 14}, and
there is only one possibilities for getting a multiple of ten: {10, 12, 14}
The probability here of getting a multiple of two is 3/6, and that of getting a multiple of ten is 1/6. But one of the outcomes is found in both result sets: 10. Getting a multiple of 10 is already included in the event that the outcome is a multiple of two. My answer here would be 3/6, or 1/2.
