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 <<<<<
The correct answer ids 100% answer choice D
The total cost that a customer should incur in its dealings with company A should be,
c = 50t + 100
For company B
c = 60t + 80
Equating these two charges
c = 50t + 100 = 60t + 80
Thus, the answer is the fourth choice.
Answer:
see explanation
Step-by-step explanation:
2 chords intersecting inside a circle , then the product of the parts of one chord is equal to the product of the parts of the other chord.
6
BE × ED = AE × CE , that is
10 × 3x = 12(2x + 1) ← distribute parenthesis by 12
30x = 24x + 12 ( subtract 24x from both sides )
6x = 12 ( divide both sides by 6 )
x = 2
then
ED = 3X = 3(2) = 6
7
RJ × JP = SJ × JQ , that is
6 × 3x = 4(4x + 1) ← distribute parenthesis by 4
18x = 16x + 4 ( subtract 16x from both sides )
2x = 4 ( divide both sides by 2 )
x = 2
then
RP = RJ + JP = 6 + 3x = 6 + 3(2) = 6 + 6 = 12
Answer:
(2,4)
Step-by-step explanation:
