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:
150
Step-by-step explanation:
To solve the problem, put 5 instead of x, so 5*3
and put 10 instead of y, so 10*1
when combined,
(5*3) * (10*1)
= 15 * 10
= 150
Hope this helps!!
Let me know if I'm wrong...
Answer:
X/360 (r^2)
Step-by-step explanation:
If X is the number of degrees of the sector, then the area will be given by
X/360 *r^2
Where r^2 is the radius of the circle. The denominator of X is 360 because the degrees of a circle add up to 360
For instance, if the sector is half the circle, then we have
180/360 *r^2 (or 0.5(360)*r^2)
