6(2+18-9)+(3x4)^2 answer

The numerator is the same number as the?

ELEN [110]

The numerator is the number of equal parts

7 0

3 years ago

1. A student took 60 minutes to answer a combination of 20 multiple-choice and extended-response questions. She took 2 minutes t

Darina [25.2K]

Answer:

1) m=15 and r =5

2) 4 and 2 ml

3) x= 0.5 and y = -1

Step-by-step explanation:

given that m multiple choice questions and r extended response questions.

Also given that a) m+r = total no of questions =20 ... i and

2m+6r = total time taken = 60 ... ii

b) Divide second equation by 2, m+3r = 30 ... iii

m+r = 20 ... i

Subtract to get 2r =10 or r =5

m = 20-5 = 15

Verify: m+r = 15+5 =20

and 2m+6r = 30+30 = 60 minutes.

Hence verified

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2) Let a litres of 20% solution and b litres of 50% solution be mixed

a) Then total volume = 6 ml = a+b ... i

Resulting solution = 30% of 6 ml = 1.8 = 0.2a+0.5b ... ii

b) Solve i and ii

b = 6-a: substitute in ii.

0.2a + 3-0.5a = 1.8

Or a = 4 ml and b = 2ml

Verify: Total volume = a+b =6ml and

concentration = 0.2(4)+0.5(2) = 1.8 = 30% of 6 ml.

Thus verified

---------------------------------

3) 2x-3y=4 ...i

2x-5y =6... ii

Because x term has the same coefficient in both the equations, elimination is easier.

i-ii gives 2y =-2 or y =-1

Substitute in i, 2x+3 =4 or x = 0.5

So answer is x = 0.5 and y =1

6 0

3 years ago

Anyone please help me

Tomtit [17]

Yeah I think it’s 12 hope that helped...

5 0

3 years ago

Read 2 more answers

A group of people buys 5 pounds of corn meal to divide equally among 6 families write a fraction or mixed number that shows how

Ivan

Answer:

5/6 pounds

Step-by-step explanation:

A group of people buys 5 pounds of corn meal to divide equally among 6 families write a fraction or mixed number that shows how many pounds of corn meal each family gets'.

Given the following :

Amount of corn meal purchased = 5 pounds

Number of people to share = 6 families

Assume, it is divided equally among them;

Then; each family gets ;

(Pounds of corn meal purchased/number of families) ;

5 / 6 pounds of corn meal will be distributed to each family.

7 0

3 years ago

The time required for an automotive center to complete an oil change service on an automobile approximately follows a normal di

PIT_PIT [208]

Answer:

a) 11.51%; b) 13 minutes

Step-by-step explanation:

We will use a z score to answer these questions. The formula for a z score is

$z=\frac{X-\mu}{\sigma}$

For part a, X is 20, the mean is 17 and the standard deviation is 2.5:

z = (20-17)/2.5 = 3/2.5 = 1.2

Using a z table, we see the area to the left of, or less than, this value is 0.8849; this means the area to the right of, or greater than, is 1-0.8849 = 0.1151. This means 11.51% of people have a time greater than 20 minutes and get half off.

For part b, we start out in the z table finding values as close to 5%, or 0.05, as possible. There are two possibilities, 0.0505 (z=-1.64) and 0.0495 (z=-1.65). Since they are equally distant from the desired value, we will use -1.645 for z. Our values for the mean and standard deviation are the same:

-1.645 = (X-17)/2.5

Multiply both sides by 2.5:

2.5(-1.645) = ((X-17)/2.5)(2.5)

-4.1125 = X-17

Add 17 to each side:

-4.1125+17 = X-17+17

12.8875 = X

This means the garage should make the guaranteed time no more than 13 minutes.

8 0

3 years ago