Sony’s class teacher informed her to select 6 out of 10 subjects, and also she told her that two of the subjects are compulsory to choose and the rest of them are of your interest. In how many ways Sony can choose her subjects?

Here are some formulas for permutations and combinations:  Permutations: The formula for permutations is nPr = n!/(n-r)! .  Permutations are used for lists of data where the order of the data matters.  Combinations: The formula for combinations is nCr = n!/[r! (n-r)!].  Combinations are used for groups of data where the order of the data doesn't matter.  Number of ways to arrange \(r\) things out of \(n\) different things: The formula is nPr = n! (n−r)! .  Number of ways to select \(r\) things out of \(n\) given things wherein \(r\le n\): The formula is nPr = r!×nCr.  nCn = 1 and nC0 =... Show more

Here are some formulas for permutations and combinations: 

Permutations: The formula for permutations is nPr = n!/(n-r)! . 
Permutations are used for lists of data where the order of the data matters. 

Combinations: The formula for combinations is nCr = n!/[r! (n-r)!]. 
Combinations are used for groups of data where the order of the data doesn't matter. 

Number of ways to arrange \(r\) things out of \(n\) different things: The formula is nPr = n! (n−r)! . 
Number of ways to select \(r\) things out of \(n\) given things wherein \(r\le n\): The formula is nPr = r!×nCr. 
nCn = 1 and nC0 = 1 
nCr = nC. (n - r):  
(n-1)! ways: If 'n' objects are arranged in a circular way and if the clockwise and anti-clockwise arrangement is different. 
C (n+ r -1 ,r) = (n + r -1 )! / r! (n – 1) !:

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