In a double-slit experiment, green light (5303 Å) falls on a double slit having a separation of 19.44 m and a width of 4.05 m. The number of bright fringes between the first and the second diffraction minima is:

For  diffraction location of  1^st  minima

y₁ =  = 0.2469D                                                                   Q                               

location of 2nd minima                                                                                  

y_{2 =  =}0.4938D                                                                     

Now for interference Path difference at P.

 = 4.8

path difference at Q

 = 9.6

So orders of maxima in between P & Q is 5, 6, 7, 8, 9

So 5 bright fringes all present between P & Q.