Answer:
The intersection is at (1,3) and the answer is in the graph. (see image below)
Step-by-step explanation:
Using pythagoras length of the other leg = sqrt ( 8^2 - 4^2) = sqrt 48 = 4 sqrt3
the ratio of the sides of the triangle = 8 : 4 :4 sqrt3 = 2:1:sqrt3 so this is a
30-60-90 degree triangle
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 most reasonable estimate for 90 days is B. 2 × 
meals.
Explanation:
- The aircraft carrier can serve 1,633,500 meals over a period of 90 days.
- The given values are A. 2 ×
, B.2 × , C.2 × 
, D.2 × 
. All the given values are in the range of 2 so it will only logical if we round off the value we have too. We round off 1,633,500 to 2,000,000.
- Suppose you multiply 2 with 100 you get 100, 2 multiplied with 100 is represented by 2 ×
so the power to which 10 is raised represents the number of zeros in the resulting value i.e. 10 is raised to the power of 2 so the resulting answer has 2 zeroes.
- Options C and D have negative powers so they will equal decimal values so only options A and B could be the answer. Since there are 6 zeroes in 2,000,000 which is equal to 2 × . So the answer is option B.
