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MathsJEE Main 22 Jan 2026, Shift 2·Q19·MCQ·Easy–moderate

Sets, Relations & Functions · Functional equations

Let ff and gg be functions satisfying f(x+y)=f(x)f(y)f(x+y) = f(x)f(y), f(1)=7f(1) = 7 and g(x+y)=g(xy)g(x+y) = g(xy), g(1)=1g(1) = 1, for all x,y∈Nx, y \in \mathbb{N}. If ∑x=1n(f(x)g(x))=19607\displaystyle\sum_{x=1}^{n}\left(\frac{f(x)}{g(x)}\right) = 19607, then nn is equal to:
  1. (1)7
  2. (2)5
  3. (3)6
  4. (4)4
We corrected a printing error in the original paper

Source printed “f(l)=7f(l) = 7” and “g(l)=1g(l) = 1” (letter l for the number 1); the missing “If” added before “∑…=19607\sum \ldots = 19607”.

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