In a young's double slit experiment 'd' distance between slit is $0.5\; mm$ and illuminated by light of $\lambda =6000 A^{\circ}$ If screen distance is 2.5m ,thedistance of third bright fringe from centre.

Question

$(a)\;1.5 \;mm \\ (b)\;3\;mm \\ (c)\;2.5\;mm \\ (d)\;9\;mm$