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:
x = 15
Step-by-step explanation:
angles 2 and 4 are supplementary so they add up to 180
2x + 10 + 4x + 80 = 180
6x + 90 = 180
6x = 90
x = 15
the soultion in 20
Step-by-step explanation:
first get the 34 hour of dogeball and get the 14 hour of basketball subtract 34 - 14 first 4 - 4 = 0 then 30 - 10 = 20
As determined by the graph, f(-9) = 9
Part A: subtract 6 from both sides
Divide by -3 on both sides
X=-3
Part B: add like terms (-2K-3k)
Add 12 to both sides
Add 5k to both sides
Divide by 5 on both sides
K=3
Part C: distribute 6 into the parentheses
Add like terms together (36-5)
Subtract 1 from both sides
Subtract 36v from both sides
Divide by -30 on both sides
-1=v