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:
The second one (2) is a lie
Step-by-step explanation:
The quantities are all proportional, with 4 donuts costing one dollar being consistant. With this, we can multiply the amount of donuts to 40, and through what we know, we can find that the donuts will cost 10 dollars. This leaves only (2) left.
Answer:
400，000，000，000
Step-by-step explanation:
2*2=4
and 5 zeros plus 6 zeros equals 11 zeros.
Answer:
Answer: First, we use Ohm's law ( V = I × R ), to find the current through the resistor. The voltage across the resistor is V = 9 V. The resistance of the resistor is R = 100 Ω. Then, we can use the power rule ( P = I × V ), to find the power dissipated by the resistor
Step-by-step explanation:
i dont know if its the right answer but here
I think they made 9 5/6sandwiches
7 1/2= 7 3/6
2 1/3=2 2/6
2 2/6+ 7 3/6= 9 5/6
