In Young’s double slit experiment, the wavelengths of red and blue lights used are \(7.5 \times 10^{-5}\) cm and \(5 \times 10^{-5}\) cm respectively. If the \(n^{th}\) bright fringe of red color coincides with \((n+1)^{th}\) bright fringe of blue colour, then the value of \( n \) is