There are 3 boys and 4 girls. We have to arrange any 1 boy at the centre and any 2 girls at corners. In how many methods these persons can be arranged.
methods for arranging 1 boy at centre = 3
methods of arranging 2 girls at corner = 4*3 = 12
methods of arranging remaining 4 persons = 4*3*2*1 = 24
so total methods = 3*12*24 = 864