Answer:
(a) 720 ways
(b) 120 ways
(c) 24 ways
Step-by-step explanation:
Given
--- number of letters
Solving (a): Number of arrangements.
We have:
So, the number of arrangements is calculated as:
This gives:
This gives:
Solving (b): DA as a unit
DA as a unit implies that, we have:
[DA] N C E R
So, we have:
So, the number of arrangements is calculated as:
This gives:
This gives:
Solving (c): NCE as a unit
NCE as a unit implies that, we have:
D A [NCE] R
So, we have:
So, the number of arrangements is calculated as:
This gives:
This gives:
Ok, so 120 pages plus the 60% of the book she has left to read will give the total number of pages.
That means that 120 pages is 40% of the book.
Make a proportion
120/40% = x/60%
72 = .4 x
x = 180 pages
I hope it helps you get it right
The work done in pushing the box is 64000 lb-ft²/s²
<h3>How to calculate the work done by the person?</h3>
Since person pushing a 40 pound box up an incline that is 30 degrees above the horizontal and 100 feet long, the work done, W is
W = mgh where
- m = mass of box = 40 lb,
- g = acceleration due to gravity = 32 ft/s² and
- h = height of incline = LsinФ where
- L = length of incline = 100 ft and
- Ф = angle of incline = 30°
So, W = mgh
W = mgLsinФ
So, substituting the values of the variables into the equation, we have
W = mgLsinФ
W = 40 lb × 32 ft/s² × 100 ftsin30°
W = 1280 lb-ft/s² × 100 ft × 0.5
W = 1280 lb-ft/s² × 50 ft
W = 64000 lb-ft²/s²
So, the work done in pushing the box is 64000 lb-ft²/s²
Learn more about work done here:
brainly.com/question/25970931
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