pl solve

Here the boys and girls need to be arranged in one single row not rows .

Now , there are 11 places . You seat the boys in alternate places starting from the first or second or third place

So boys can be seated in 3   x  5 !  ways .

Now there is no problem in seating the girls , they can be together too. So 6 ! ways

So together , they can be seated in 3 x 5!  x 6! ways