Number of ways to select 3 books from 13 books for adoption is 286 .
<u>Step-by-step explanation:</u>
A Permutation is an ordered Combination. When the order does matter it is a Permutation. There are basically two types of permutation:
- Repetition is Allowed: such as the lock above. It could be "333".
- No Repetition: for example the first three people in a running race. You can't be first and second.
Formula is given by:
, where n is the number of things to choose from, and we choose r of them, no repetitions, order matters. Here , n=13 , r=3.
⇒ 
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∴ Number of ways to select 3 books from 13 books for adoption is 286 .
Answer:
x ≤ -259/9
Step-by-step explanation:
Change into a number equation 9(x + 26) ≤ -25
The expanded form is adding all the digits so the answer is
700+50+7+0.9+0.02+0.003
Answer:
They are identical triangles.
Step-by-step explanation:
Angles in a triangle add up to 180 degrees.
The triangle with 39 and 90 has a missing angle of 51 degrees, and the triangle with 51 and 90 vice versa.