1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Illusion [34]
4 years ago
5

Bertha buys electricity from a company that offers a choice of two tariffs. Both have a daily charge of $0.20 regardless of how

much electricity is used. The ‘standard’ tariff charges $0.10 for each unit used, while the ‘day/night tariff’ charges $0.12 for each unit consumed between 06:00 and 22:00 but only $0.05 for each unit consumed between 22:00 and 06:00, when total demand on the electricity network is low. Bertha is currently on the standard tariff. What is the highest proportion of her total electricity consumption that Bertha’s daytime use can be, so that she would not be paying more if she switched to the ‘day/night’ tariff?
A. 5/17
B. 2/5
C. 5/7
D. 17/20
Mathematics
1 answer:
Alenkasestr [34]4 years ago
6 0

Answer: D ( 17/20)

Step-by-step explanation:

The two choices are:

The ‘standard’ tariff charges = $0.10 per unit

The ‘day/night tariff’ = $0.12 per unit for each unit consumed between 06:00 and 22:00 but only $0.05 for each unit consumed between 22:00 and 06:00

The day time is between 22:00 and 06:00

Time = 22 - 6 = 16 hours

Let assume that the charges are unit per hour.

For standard tariff = (16 × 0.10) + 0.2

Standard tariff = 1.6 + 0.2 = 1.8

For day/night = (16 × 0.12) + 0.2

= 1.92 + 0.2

= 2.12

The proportion will be

1.8/2.12 = 17/20 ( approximately)

You might be interested in
What two rational expressions sum to 2x+3/x^2-5x+4
Anni [7]

Answer:

\frac{2x + 3}{(x- 1)(x - 4)} = \frac{-5}{3(x- 1)} + \frac{11}{3(x - 4)}

Step-by-step explanation:

Given the rational expression: \frac{2x + 3}{x^2 - 5x + 4}, to express this in simplified form, we would need to apply the concept of partial fraction.

Step 1: factorise the denominator

x^2 - 5x + 4

x^2 - 4x - x + 4

(x^2 - 4x) - (x + 4)

x(x - 4) - 1(x - 4)

(x- 1)(x - 4)

Thus, we now have: \frac{2x + 3}{(x- 1)(x - 4)}

Step 2: Apply the concept of Partial Fraction

Let,

\frac{2x + 3}{(x- 1)(x - 4)} = \frac{A}{x- 1} + \frac{B}{x - 4}

Multiply both sides by (x - 1)(x - 4)

\frac{2x + 3}{(x- 1)(x - 4)} * (x - 1)(x - 4) = (\frac{A}{x- 1} + \frac{B}{x - 4}) * (x - 1)(x - 4)

2x + 3 = A(x - 4) + B(x - 1)

Step 3:

Substituting x = 4 in 2x + 3 = A(x - 4) + B(x - 1)

2(4) + 3 = A(4 - 4) + B(4 - 1)

8 + 3 = A(0) + B(3)

11 = 3B

\frac{11}{3} = B

B = \frac{11}{3}

Substituting x = 1 in 2x + 3 = A(x - 4) + B(x - 1)

2(1) + 3 = A(1 - 4) + B(1 - 1)

2 + 3 = A(-3) + B(0)

5 = -3A

\frac{5}{-3} = \frac{-3A}{-3}

A = -\frac{5}{3}

Step 4: Plug in the values of A and B into the original equation in step 2

\frac{2x + 3}{(x- 1)(x - 4)} = \frac{A}{x- 1} + \frac{B}{x - 4}

\frac{2x + 3}{(x- 1)(x - 4)} = \frac{-5}{3(x- 1)} + \frac{11}{3(x - 4)}

7 0
3 years ago
Please help<br> x+yz<br> When x=4 y= -2 z= 4/5<br> Please explain on how you got your work.
Rom4ik [11]
Substitute the numbers for the variables

4+(-2)(4/5)

easier if you turn 4/5 into a decimal

4+(-2)(0.8)

multiply -2 and 0.8

4+(-1.6)

add

4-1.6

answer is 2.4




3 0
4 years ago
Read 2 more answers
Please answer both questions, I will report and delete unnecessary answers, or answer just trying to steal points.
Nostrana [21]

Answer:

1.  3x-2y=-6

2. 3x+2y=6

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
The temperature on a particular day started at –13°F. It rose steadily by 3° each hour. The function y = –13 + 3x models the tem
alex41 [277]
The function you're given is in point-slope format, which is one of the easiest ones to graph. The basic form of the format is;

y=ax+b

Where a is the slope and b is the y-intercept.

As you can see, in y=-13+3x, the positions of a and b are switched, but it is essentially the same question.

From here we can tell that the y-intercept is -13, meaning that there is a point on the line that rests at (0,-13)

To find the other points, we can do rise-over-run using the slope of 3 given to us. What happens here is that for every 1 unit you go to the right (positive), you rise 3 units up.

For example, if we perform this on the y-intercept (0,-13):

(0+1, -13+3)
(1,-10)

With these two points, you can graph the line representing the temperature. 
6 0
4 years ago
1,225 rides was the total number of rides that 35 friends took on a Ferris wheel.
Jet001 [13]
Each friend would have taken a total of 35 rides each. 

This can be verified by multiplying 35 by 35 to get 1225.
8 0
3 years ago
Other questions:
  • The basketball court in the park is a rectangle. Two of the sides are 84 feet long, and the other two sides are 50 feet long. Wh
    7·2 answers
  • Two factors of 30 add up to 9 what are they
    8·1 answer
  • Which of the following ratios are proportional to 60⁄1? Check all that are true. 300⁄5 30⁄2 90⁄4 180⁄3 120⁄2
    15·1 answer
  • Please help! will give correct answer brainliest!
    9·1 answer
  • 4/5 + 8/10 plz help with this
    14·2 answers
  • What is the value of u?
    11·1 answer
  • Directions: Solve each equation. Show<br> -26 = -9x + 10<br><br> What is the answer?
    13·1 answer
  • I hope the quality is good enough to read. Sorry
    15·1 answer
  • 1.25 is what percent of 112
    15·1 answer
  • The first three steps in writing f(x) = 40x 5x2 in vertex form are shown. write the function in standard form. f(x) = 5x2 40x fa
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!