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 <<<<<
Here are some simple equations that can be a life saver with this stuff :
vol of a sphere =
Circumference =
sorry this might not be very helpful. I haven't don't this since last year. You basically have to work backwards. so plug in 972 for V and then do (3/4)×3.14.
then take the answer u got for ^^ and divide it by 2? not sure.
Answer:
The angles are 79.45, 59.02 and 41.53 degrees to the nearest hundredth.
Step-by-step explanation:
We have a triangle with sides of length 8.6, 5.8 and 7.5 feet.
Using the Cosine Rule to find the measure of the angle opposite the side of length 8.6 feet:
cos X = (8.6^2 - 5.8^2 - 7.5^2) / ( -2*5.8*7.5)
= 0.18310
X = 79.45 degrees.
We can now find another angle using the sine rule:
8.6 / sin 79.45 = 7.5/ sin Y
sin Y = (7.5 * sin 79.45) / 8.6
Y = 59.02 degrees
So the third angle = 180 - 79.45 - 59.02
= 41.53 degrees.
Answer:-0.2
Step-by-step explanation:
Ask Siri lol
Answer: (-5,0)
Step-by-step explanation:
-4x + 5y = 20 the x intercept is when y is zero so input zero into the equation and solve for x.
-4x + 5(0) = 20
-4x = 20
x = -5
