How many ways are possible to arrange 4 boys and 3 girls for a dinner, if there are two straight benches of capacity 5 and 2 persons for their sitting?
Total no. of persons = 7
Since benches are straight, therefore arranging them in benches of capacity 5 and 2 persons is
equivalent to arranging them in a straight bench of capacity 7 persons.
Total no. of methods
= 7*6*5*4*3*2*1 = 5040