JEE Mains · Maths · STD 12 - 1. relation and function
The total number of functions,\(f:\{1,2,3,4\} \cdot\{1,2,3,4,5,6\}\) such that \(f (1)+ f (2)= f (3)\), is equal to .
- A \(60\)
- B \(90\)
- C \(108\)
- D \(126\)
Answer & Solution
Correct Answer
(B) \(90\)
Step-by-step Solution
Detailed explanation
\(A =\{1,2,3,4\}\) \(B =\{1,2,3,4,5,6\}\) Here \(f(3)\) can be \(2, 3, 4, 5, 6\) \(f (3)=2,( f (1), f (2)) \rightarrow(1,1) \rightarrow 6 \text { cases }\) \(f (3)=3,( f (1), f (2)) \rightarrow(1,2),(2,1)\) \(\rightarrow 2 \times 6=12 \text { cases }\)…
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