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3 years ago

Ali used the expressed 8+25×2-45 to find how many CDs he has. how many CDs dose he have

Mathematics

2 answers:

MatroZZZ [7]3 years ago

7 0

Ali has 13 CD's

Here's how I got my answer:

Step 1: Simplify $25 * 2$ to 50. Which leaves us with $8 + 50 - 45$

Step 2: Simplify $50 - 45$ to 5. Which leaves us with $8 + 5$ .

Step 3: Simplify $8 + 5$ , to get your answer, 13.

andrew11 [14]3 years ago

5 0

13 is the answer.

always use the phrase PEMDAS

P= parenthesis

E= exponents

M= multiply

D= divide

A= add

S=subtract

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An object is dropped off a building that is 144 feet tall. After how many seconds does the object hit the ground? (d=16t^2)

andrew-mc [135]

Answer:

after 3 seconds, the object hits the ground.

Hope this helps :)

7 0

3 years ago

John, Joe, and James go fishing. At the end of the day, John comes to collect his third of the fish. However, there is one too m

Dmitry [639]

Answer:

The minimum possible initial amount of fish: $52$

Step-by-step explanation:

Let's start by saying that

$x$ = is the initial number of fishes

John:

When John arrives:

he throws away one fish from the bunch

$x-1$

divides the remaining fish into three.

$\dfrac{x-1}{3} + \dfrac{x-1}{3} + \dfrac{x-1}{3}$

takes a third for himself.

$\dfrac{x-1}{3} + \dfrac{x-1}{3}$

the remaining fish are expressed by the above expression. Let's call it John

$\text{John}=\dfrac{x-1}{3} + \dfrac{x-1}{3}$

and simplify it!

$\text{John}=\dfrac{2x}{3} - \dfrac{2}{3}$

When Joe arrives:

he throws away one fish from the remaining bunch

$\text{John} -1$

divides the remaining fish into three

$\dfrac{\text{John} -1}{3} + \dfrac{\text{John} -1}{3} + \dfrac{\text{John} -1}{3}$

takes a third for himself.

$\dfrac{\text{John} -1}{3}+ \dfrac{\text{John} -1}{3}$

the remaining fish are expressed by the above expression. Let's call it Joe

$\text{Joe}=\dfrac{\text{John} -1}{3}+ \dfrac{\text{John} -1}{3}$

and simiplify it

$\text{Joe}=\dfrac{2}{3}(\text{John}-1)$

since we've already expressed John in terms of x, we express the above expression in terms of x as well.

$\text{Joe}=\dfrac{2}{3}\left(\dfrac{2x}{3} - \dfrac{2}{3}-1\right)$

$\text{Joe}=\dfrac{4x}{9} - \dfrac{10}{9}$

When James arrives:

We're gonna do this one quickly, since its the same process all over again

$\text{James}=\dfrac{\text{Joe} -1}{3}+ \dfrac{\text{Joe} -1}{3}$

$\text{James}=\dfrac{2}{3}\left(\dfrac{4x}{9} - \dfrac{10}{9}-1\right)$

$\text{James}=\dfrac{8x}{27} - \dfrac{38}{27}$

This is the last remaining pile of fish.

We know that no fish was divided, so the remaining number cannot be a decimal number. We also know that this last pile was a multiple of 3 before a third was taken away by James.

Whatever the last remaining pile was (let's say $n$ ), a third is taken away by James. the remaining bunch would be $\frac{n}{3}+\frac{n}{3}$

hence we've expressed the last pile in terms of n as well. Since the above 'James' equation and this 'n' equation represent the same thing, we can equate them:

$\dfrac{n}{3}+\dfrac{n}{3}=\dfrac{8x}{27} - \dfrac{38}{27}$

$\dfrac{2n}{3}=\dfrac{8x}{27} - \dfrac{38}{27}$

L.H.S must be a Whole Number value and this can be found through trial and error. (Just check at which value of n does 2n/3 give a non-decimal value) (We've also established from before that n is a multiple a of 3, so only use values that are in the table of 3, e.g 3,6,9,12,..

at n = 21, we'll see that 2n/3 is a whole number = 14. (and since this is the value of n to give a whole number answer of 2n/3 we can safely say this is the least possible amount remaining in the pile)

$14=\dfrac{8x}{27} - \dfrac{38}{27}$

by solving this equation we'll have the value of x, which as we established at the start is the number of initial amount of fish!

$14=\dfrac{8x}{27} - \dfrac{38}{27}$

$x=52$

This is minimum possible amount of fish before John threw out the first fish

8 0

2 years ago

A card is being drawn from a standard deck of playing cards. Find each probability.

EastWind [94]

These are 6 questions and 6 answers.

To find each probability we will use the definition of probability:

Probability = number of positive outcomes / number of total possible outcomes

1) P(Jack or ten)


Answer: 2/13 ≈ 0.12


Justification:

i) Positive outcomes: A standard deck of cards has 4 jacks and 4 tens, then those are 4 + 4 = 8 different positive outcomes.

ii) Possible outcomes: a standard deck of cards has 52 different cards, so, that is a total of 52 different possible outcomes

iii) Probability, P

P = number of positive outcomes / number of total possible outcomes

P = 8 / 52 = 2/13 ≈ 0.15

 2.P(red or black)


Answer: 1

Justification:

i) Positive outcomes

Half of the cards are red and half of the cards are black, so they both add for the total of the cards = 52

ii) Possible outcomes: 52 cards

iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 52 / 52 = 1

 3.P(queen or club)


Answer: 4/13 ≈ 0.31

Justification:

i) Positive outcomes

There are 4 Queens.

There are 1/4 of 52 clubs = 1/4 × 52 = 13 clubs.

But you cannot add all of them, because one club is the Quenn of Clubs.

Then, the total number of different Queens and clubs is 4 + 13 - 1 = 16

ii) Possible outcomes: 52 different cards

iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 16 /52 = 4 / 13 ≈ 0.31

 4.P(red or ace)


Answer: 7 / 13 ≈ 0.54

Justification:

i) Positive outcomes

Half of the cards are red: 26

There are 4 aces.

Since 2 aces are red, the number of different red and aces cards is: 26 + 4 - 2 = 28

ii) Possible outcomes: 52 different outcomes

iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 28 / 52 = 7 / 13 ≈ 0.54

 5.P(diamond or black)


Answer: 1/2 = 0.5

Justification:

i) Positive outcomes

There are 52 / 4 = 13 diamonds

There are 26 black cards.

All the diamonds are black cards.

Then, the number of different diamond or black cards is 13 + 26 - 13 = 26

ii) Possible outcomes: 52 different cards.

iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 26 / 52 = 1/2 = 0.5

6.P(face card or spade)

Answer: 11/26 ≈ 0.42

Justification:

i) Positive outcomes

Face cards are jacks, queens and kings. That is 3 × 4 = 12 different cards.

The spades are 13 cards.

Since, 3 of the faces are spade cards, the number of different cards of those types are 12 + 13 - 3 = 22

ii) Possible outcomes: 52 different cards

iii) Probaility, P

P = number of positive outcomes / number of total possible outcomes

P = 22 / 52 = 11 / 26 ≈ 0.42

4 0

2 years ago

Teddy wants to wrap a gift she bought for her best friends birthday. Determine how much wrapping paper she will need to cover th

laiz [17]

Answer:

127.2

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

Lin lines the bottom of her first pan with aluminum foil. The area of the rectangular piece of foil 11 1 4 is square inches. Its

prisoha [69]

Answer:

Length =

= 5/2 inches or 2 1/2 inches

Step-by-step explanation:

Lin lines the bottom of her first pan with aluminum foil. The area of the rectangular piece of foil 11 1 4 is square inches. Its length is 4 1 2 inches. What is the width of the foil? Explain your reasoning.

Area of rectangle = Length × Width

Widths = Area/Length

The area of the rectangular piece of foil 11 1/4 is square inches.

Its length is 4 1 /2 inches.

Hence:

Length = 11 1/4 /4 1/2

= 45/4 ÷ 9/2

= 45/4 × 2/9

= 5/2 inches

= 2 1/2 inches

6 0

3 years ago