All categories

3 years ago

From eight different books, in how many ways can any four of them be arranged side by side on a bookshelf?

1 answer:

3 0

First we calculate how many ways you can choose four books from a set of eight.
We use the formula n! / [r! * (n-r)!]

8! / [4! * 4!]

= 8*7*6*5 / 4*3*2*1 = 70 ways

Then we have to calculate how many permutations can be made from 4 objects which equals 4*3*2*1 = 24

So, the TOTAL number of ways = 70 * 24 = 1,680

You might be interested in

The stock market dropped 220 points on Monday. It lost another 48 points on Tuesday, and on Wednesday, it gained 96 points. What

MissTica

48 points gained in those 3 days.

Subtract 220 with 48, then add 96. Last step would be subtracting 220 with the amount they have now in those 3 days to find how much points the stock market gained in those 3 days.

Subtract 220-48.It‘ll be 172.

Add 172 with 96. 172+96=268.

Subtract 268 with how much points the stock market had 3 days ago. 268-220.

Sot eh stock market gained 48 points in 3 days.

4 0

3 years ago

Giving brainless! Don’t answer if you don’t know I’ll flag you.

GenaCL600 [577]

Answer:

The sales tax is $0.40

Step-by-step explanation:

10 x 0.04 = 0.4

0.04 is 40% when multiplying

4 0

3 years ago

'Quiz: Math Review Quiz

pentagon [3]

Answer:

The tax rate is 4.3%

Step-by-step explanation:

First, we have to assume $2.79 is 100%. We know that x% equals 0.12 of the output value. Now we have two simple equations: 100%=2.79 and x%=0.12.

Then, 100%/x%=2.27/0.12 and that gives us 4.3%!

Hope this helps.

8 0

3 years ago

To decorate for a party, Simon needs 1,850 centimeters of colorful streamers. If the ratio of meters to centimeters is 1 : 100,

nordsb [41]

The simple answer is 18.5m

3 0

3 years ago

Read 2 more answers

The length of rectangle is 3 more than twice the width

kykrilka [37]

Answer:

The length of a rectangle is 3” more than twice the width. The area of the rectangle is 150 in^2. Find the dimensions of the rectangle.

Wyzant

MATH QUADRATIC FORMULA

Kyle C. asked • 05/05/16

The length of a rectangle is 3” more than twice the width. The area of the rectangle is 150 in^2. Find the dimensions of the rectangle.

ANSWER

ABOUT THIS TUTOR ›

We know that Area = Length x Width

in this case, L = 2W + 3 and A = 150in2

so, 150in2 = W x (2w + 3)

150in2 = 2W2 + 3W

rearranging, 2W2 + 3W - 150in2 = 0

we need to use the quadratic formula to solve this equation

that formula is [-b±(√b2 -4ac)]/2a

a = 2, b = 3, c = -150

inserting those values, we get [-3±(√32 -4•2•-150)]/2•2

which becomes (-3±√1209)/4

we get (-3 ± 34.771)/4

we can discard the negative value, because no length can be negative

so, W ≅ 7.942 inches

then L = 2W + 3 ≅ 18.886 inches

Proof: 7.942in x 18.886in ≅ 149.99

HOPE IT'S HELPFUL

THANK YOU

4 0

3 years ago