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 <<<<<
Add 2.2 to each side so 0.3z = 5.2 - 0.5z -0.8z
add 0.5z to each side so 0.8z = 5.2 - 0.8z
add 0.8z to each side so 1.4z = 5.2
divide each side by 1.4 so z = 3.71428571
Answer:
(B)
Step-by-step explanation:
PRINCIPAL AMOUNT(p) = $400
RATE (r)= 250% = 2.5
INTEREST = $80
t = time (in days) = t/365
By using the formula,
r = 
2.5 = 
t = 
t = 29.2
t = 29 days (approx)
Hence option (B) is correct.
Y + 3 = x - 1
- 3 - 3
y = x - 4
The slope-intercept form of the equation of the line is y = x - 4.
Hi!
To solve exponental equations, multiply the exponents.
4·5=20
The answer is
Hope this helps! :)
-Peredhel
