Answer:
2520 patterns
Step-by-step explanation:
In 'n' 10! ways, books can be arranged. But, there are also 5! permutation of blue books 'n1', 2! permutation of identical green books 'n2', and 3! permutation identical black books 'n3'.
Therefore, for non identical arrangements:

= 2520
Therefore, the books can be arranged on a shelf in 2520 patterns
The answer is 7859
I did it and got it right.....
Option c : 9 is the answer.
Explanation:
The expression is 
We need to determine the subtracted value of the expression.
From the expression we can see that the expression contains two negative signs.
To simplify the expression, we know that, When we multiply two negative numbers then the product is always positive.
This means 
Thus, the expression can be written as

Adding the two numbers, we get,

Thus, the value of the expression is 9.
Hence, Option c is the correct answer.
10,11,15 is not right triangle
30,40,50 is right triangle
9,13,16 is not right angel
16,30,34 is right triangle