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:
It is 7.5%.
Step-by-step explanation:
15 x
200 100
1500/200 = 7.5
Answer:
3 movie tickets would cost 44.8 5 popcorns would cost 85
Step-by-step explanation:
29.4 divided by 2 equals 14.7
29.4 plus 14.7 equals 44.8
68 divided by 4 17
68 plus 17 equals 85
Running 2 miles at 8:15 per mile takes 16:30 minutes.
Running 3 miles at 7:12 per mile takes 21:36 minutes.
The total running time is 16:30 + 21:36 = 38:06 minutes. That length of time after 6:52 am is 7:30:06 am.
You get home for breakfast at 6 seconds past 7:30 am.
Answer:
100% chance of this happening.
Step-by-step explanation:
The chances of this happening = 100% because all the numbers are greater than 0.
