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
Lemur [1.5K]
3 years ago
10

Amy has four more 20c coins than 5c coins. The total value of all her 20c and 5c is $3.80. How many 5c coins does Amy have?

Mathematics
1 answer:
skelet666 [1.2K]3 years ago
6 0

Answer:

Amy has 12 5¢ coins

Step-by-step explanation:

Let <em>x</em> represent 20¢ coins and <em>y</em> represent 5¢ coins.

Amy has four more 20¢ coins than 5¢ coins. Hence:

x=y+4

And the total value of all her coins is $3.80. Thus:

0.2x+0.05y=3.8

This yields a system of equations:

\displaystyle \begin{cases} x=y+4 \\ 0.2x+0.05y=3.8\end{cases}

We can solve by substitution. Substitute the first equation into the first:

\displaystyle 0.2(y+4)+0.05y=3.8

Distribute:

\displaystyle 0.2y+0.8+0.05y=3.8

Combine like terms:

\displaystyle 0.25y = 3

And divide both sides by 0.25. Hence:

y=12

Thus, Amy has 12 5¢ coins.

Using the first equation:

x=y+4

Substitute:

x=(12)+4=16

Thus, Amy has 16 20¢ coins.

In conclusion, Amy has 12 5¢ coins and 16 20¢ coins.

You might be interested in
Suppose Burger King has run a major advertising campaign in the hopes of increasing monthly sales. To investigate the effectiven
Alexxandr [17]

Answer:

The right answer is:

a.H0: μd = 0; H1: μd > 0

Step-by-step explanation:

The claim that want to be tested is that the sales were significantly increased after the commercial, indicanting that the advertisement campaign was effective.

This claim is usually expressed in the alternative hypothesis as it has to have enough evidence to prove that it is true.

Then, the alternative hypothesis H1 should state that the difference (sales after - sales before) is higher than 0.

The null hypothesis would state that the difference is not significantly different from 0, or, in other words, that the sales are the same before and after and that the variation is due to pure chance.

Then, the null hypothesis H0 would state that the difference is equal to 0.

The right answer is:

a.H0: μd = 0; H1: μd > 0

4 0
3 years ago
if you have 20 yards of ribbon and need to vut it into 2 yard lengths how many cuts do you have to make. step by step if u can i
wlad13 [49]

Answer:

10

Step-by-step explanation:

Given: 20 yards of ribbon in total. Need to make 2 yards each.

To find out how many yards you need to cut, divide:

20 / 2 = 10

So, you need to make 10 cuts for the 20 yards.

Hope this helped.

7 0
3 years ago
Read 2 more answers
Find the Slope using the Slope Formula ​
ExtremeBDS [4]
Answer: -1

2-1=1
1/-3+2
1/-1
=-1
7 0
3 years ago
The third term in an arithmetic sequence is 14 and the fifth term is 20. If the first term is a1, which is an equation for the n
Kruka [31]

Answer:

The equation for nth term is 3n + 5.

Step-by-step explanation:

Let a1 be a,

a3 = a + (n - 1)d

or, 14 = a + (3 - 1)d

so, 14 = a + 2d

Now,

a5 = a + (n - 1)d

or, 20 = a + (5 - 1)d

or, 20 = a + 4d

now,

a + 4d = 20

a + 2d = 14

now,

a + 4d - ( a + 2d) = 20 - 14

or, a + 4d - a - 2d = 6

or, 2d = 6

so, d = 3

Now,

a + 2d = 14

or, a + 2(3) = 14

or, a = 14 - 6

so, a = 8

Now,

an = a + (n - 1)d

or, an = 8 + (n - 1)3

or, an = 8 + 3n - 3

so, an = 3n + 5

5 0
3 years ago
For each arithmetic sequence find d and the missing terms: a) 3, ?, ?, 10.5
MakcuM [25]

Answer:

b

Step-by-step explanation:

8 0
3 years ago
Other questions:
  • Find the values for each function for x = 0,1,2,3, and 4. Analyze the pattern in the outputs to determine if the sequence is ari
    8·1 answer
  • Please I need help with this one
    9·1 answer
  • 3. You have a job where you make $15 an hour. You want to
    8·1 answer
  • A baseball has a 15 cm diameter what is the voulme of the contents of the ball
    14·1 answer
  • A machine shop produces metal frames on two different machines. The average daily production on machine 1 is 300 frames, and the
    15·1 answer
  • Which problem can we solve with 27 : 3?
    14·1 answer
  • A taxi driver charges a fixed rate of r to pick up a passenger. In addition, the taxi driver charges a rate of m for each mile d
    10·1 answer
  • I'm not sure how to do this
    5·1 answer
  • 10)
    13·1 answer
  • The blueprint for Moreno​'s living room has a scale of 2 inches equals 3 feet. The family wants to use a scale of 1 inch equals
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!