If `.^(n)C_(r-1): .^(n)C_(r): .^(n)C_(r+1)=3:4:5`, find the values of n and r.

Explanation

To solve the problem, we start with the given ratios of combinations:

\[ \binom{n}{r-1} : \binom{n}{r} : \binom{n}{r+1} = 3 : 4 : 5 \]

This can be expressed as:

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