All categories

1 year ago

9 burgers and 1 doughnut cost $31.30. 3 doughnuts and 6 burgers cost $26.70. Find the cost of 2 burgers.

Mathematics

2 answers:

kirill [66]1 year ago

5 0

Step-by-step explanation:

Let assume that

Cost of 1 burger = $ x

Cost of 1 doughnuts = $ y

According to statement, 9 burgers and 1 doughnut cost $ 31.30

$\begin{gathered}\sf \: 9x + y = 31.3 \\ \\ \end{gathered}$

$\begin{gathered}\sf\implies \sf \: y = 31.3 - 9x - - - (1) \\ \\ \end{gathered}$

According to statement again, 3 doughnuts and 6 burgers cost $ 26.70

$\begin{gathered}\sf \: 6x + 3y = 26.7 \\ \\ \end{gathered}$

$\begin{gathered}\sf \: 3(2x + y) = 26.7 \\ \\ \end{gathered}$

$\begin{gathered}\sf \: 2x + y = 8.9 \\ \\ \end{gathered}$

On substituting the value of y from equation (1), we get

$\begin{gathered}\sf \: 2x + 31.3 - 9x = 8.9 \\ \\ \end{gathered}$

$\begin{gathered}\sf \: 31.3 - 7x = 8.9 \\ \\ \end{gathered}$

$\begin{gathered}\sf \: - 7x = 8.9 - 31.3 \\ \\ \end{gathered}$

$\begin{gathered}\sf \: - 7x = - 22.4 \\ \\ \end{gathered}$

$\begin{gathered}\bf\implies \: x = 3.2 \\ \\ \end{gathered}$

So,

Cost of 2 burgers = 3.2 × 2 = <u>$ 6.4</u>

Bumek [7]1 year ago

3 0

$\qquad \qquad \bf \huge\star \: \: \large{ \underline{Answer} } \huge \: \: \star$

2 burgers cost $ 6.40

$\textsf{ \underline{\underline{Steps to solve the problem} }:}$

We need to make linear equations, to solve this problem.

let the cost of each burger be x, and that of each doughnut be y.

$\qquad❖ \: \sf \:9x + y = 31 .30$

$\qquad❖ \: \sf \:y = (31 . 30 - 9x)$

put value of y in other equation.

$\qquad❖ \: \sf \:6x + 3y = 26.70$

$\qquad❖ \: \sf \:6x + 3(31.3 - 9x) = 26.70$

$\qquad❖ \: \sf \:6x + 93.90 - 27x = 26.70$

$\qquad❖ \: \sf \:6x - 27x = 26.70 - 93.90$

$\qquad❖ \: \sf \:27x - 6x = 93.90 - 26.70$

$\qquad❖ \: \sf \:21x =67 .20$

$\qquad❖ \: \sf \:x = 67.20 \div 21$

$\qquad❖ \: \sf \:x = 3.20$

So, cost of each burger is x = $ 3.20

$\qquad \large \sf {Conclusion} :$

Therefore, cost of two burgers is :

2 × 3.20 = $ 6.40

You might be interested in

Is the underlined verb in the sentence regular or irregular?

Maurinko [17]

The answer is irregular because speak is the base word and spoke is its past word

4 0

3 years ago

Read 2 more answers

ray uses a fourth of a gallon of gasoline to drive a distance of 5 1/2 miles at this rate how many miles can you drive on one ga

KIM [24]

On average you get like about 12 to 14 miles a gallon

4 0

2 years ago

Read 2 more answers

Question 15 A party rental company has chairs and tables for rent. The total cost to rent 8 chairs and 3 tables is $38 . The tot

SIZIF [17.4K]

Answer:

Each table is $6 and each chair is $2.50

Step-by-step explanation:

6 0

2 years ago

John runs a computer software store. Yesterday he counted 123 people who walked by the store, 56 of whom came into the store. Of

vaieri [72.5K]

Answer:

a) There is a 45.53% probability that a person who walks by the store will enter the store.

b) There is a 41.07% probability that a person who walks into the store will buy something.

c) There is a 18.70% probability that a person who walks by the store will come in and buy something.

d) There is a 58.93% probability that a person who comes into the store will buy nothing.

Step-by-step explanation:

This a probability problem.

The probability formula is given by:

$P = \frac{D}{T}$

In which P is the probability, D is the number of desired outcomes and T is the number of total outcomes.

The problem states that:

123 people walked by the store.

56 people came into the store.

23 bought something in the store.

(a) Estimate the probability that a person who walks by the store will enter the store.

123 people walked by the store and 56 entered the store, so $T = 123, D = 56$ .

$P = \frac{D}{T} = \frac{56}{123} = 0.4553$

There is a 45.53% probability that a person who walks by the store will enter the store.

(b) Estimate the probability that a person who walks into the store will buy something.

56 people came into the store and 23 bought something, so $T = 56, D = 23$ .

$P = \frac{D}{T} = \frac{23}{56} = 0.4107$

There is a 41.07% probability that a person who walks into the store will buy something.

(c) Estimate the probability that a person who walks by the store will come in and buy something.

123 people walked by the store and 23 came in and bought something, so $T = 123, D = 23$ .

$P = \frac{D}{T} = \frac{23}{123} = 0.1870$

There is a 18.70% probability that a person who walks by the store will come in and buy something.

(d) Estimate the probability that a person who comes into the store will buy nothing.

Of the 56 people whom came into the store, 23 bought something. This means that 56-23 = 33 of them did not buy anything. So:

$D = 33, T = 56$

$P = \frac{D}{T} = \frac{33}{56} = 0.5893$

There is a 58.93% probability that a person who comes into the store will buy nothing.

8 0

2 years ago

Write an irrational number that can be added to the irrational number the square root of 15 to get a rational sum of 2

aniked [119]

Answer:

Step-by-step explanation:

if u is an irrational number added to a rational number (sqrt 15) to yield 2, then that would mean u would = root -1.78.....

which means you wouldn't have a real solution. if you want a complex answer, it would be sqrt(1.78)i

7 0

2 years ago

9 burgers and 1 doughnut cost $31.30. 3 doughnuts and 6 burgers cost $26.70. Find the cost of 2 burgers.​

9 burgers and 1 doughnut cost $31.30. 3 doughnuts and 6 burgers cost $26.70. Find the cost of 2 burgers.