Answer:
6:8
6/8 or 3/4
Step-by-step explanation:
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:
7 cents per gallon if his tank was completely empty upon filling
Step-by-step explanation:
55.23/21=2.63 per gallon at original gas station
2.63-2.56=.07 per gallon saved
Answer:
x = -7/40
, y = -11/20
Step-by-step explanation:
Solve the following system:
{12 x - 2 y = -1 | (equation 1)
4 x + 6 y = -4 | (equation 2)
Subtract 1/3 × (equation 1) from equation 2:
{12 x - 2 y = -1 | (equation 1)
0 x+(20 y)/3 = (-11)/3 | (equation 2)
Multiply equation 2 by 3:
{12 x - 2 y = -1 | (equation 1)
0 x+20 y = -11 | (equation 2)
Divide equation 2 by 20:
{12 x - 2 y = -1 | (equation 1)
0 x+y = (-11)/20 | (equation 2)
Add 2 × (equation 2) to equation 1:
{12 x+0 y = (-21)/10 | (equation 1)
0 x+y = -11/20 | (equation 2)
Divide equation 1 by 12:
{x+0 y = (-7)/40 | (equation 1)
0 x+y = -11/20 | (equation 2)
Collect results:
Answer: {x = -7/40
, y = -11/20
Answer:
90
Step-by-step explanation:
$5.29 * 16.3 = $86.227
=$86.23
86.23 could be rounded up to 90
