All categories

2 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

Find the value of the lettered angles in each of the following ( see image ).

Arisa [49]

Step-by-step explanation:

here's the solution :-

1.) =》f = 90°

( because angle made by diameter on circumference of the circle measures 90° )

2.) =》here,

g + f + 56° = 180°

( because the sum of all interior angles of the triangle measures 180° )

=》g + 90° + 56° = 180°

=》g + 146° = 180°

=》g = 180° - 146°

=》g = 34°

3.) h = 56°

( since, they form alternate interior pair which are equal )

4 0

2 years ago

Read 2 more answers

PLZ HELP 25 POINTS AND WILL MARK BRAINLIEST Divide 3/4 ÷ 1/8 = ____.

faust18 [17]

Answer:

Step-by-step explanation:

3/4 ÷ 1/8

Copy dot flip

3/4 * 8/1

Rewriting

3/1 * 8/4

3/1 * 2/1

3 0

3 years ago

Read 2 more answers

Pls answer soon we are timed

tamaranim1 [39]

Answer:

the blue model

20 birds in all

Step-by-step explanation:

8 0

3 years ago

If N/8+6=58, then N equals?

GaryK [48]

N equals 416

Hope this helps!

8 0

3 years ago

Read 2 more answers

A software developer wants to know how many new computer games people buy each year. Assume a previous study found the standard

Marrrta [24]

Answer:

The minimum sample size required to ensure that the estimate has an error of at most 0.14 at the 95% level of confidence is n=567.

Step-by-step explanation:

We have to calculate the minimum sample size n needed to have a margin of error below 0.14.

The critical value of z for a 95% confidence interval is z=1.96.

To do that, we use the margin of error formula in function of n:

$MOE=\dfrac{z\cdot \sigma}{\sqrt{n}}\\\\\\n=\left(\dfrac{z\cdot \sigma}{MOE}\right)^2=\left(\dfrac{1.96\cdot 1.7}{0.14}\right)^2=(23.8)^2=566.42\approx 567$

The minimum sample size to have this margin of error is n = 567.

3 0

2 years ago