Question 1039938
The next seat can be any of the boys or
any of the girls, so there are 
{{{ 7! = 5040 }}} ways they can be seated
(b)
The boys will have to be in positions
1,3,5, and 7
The girls have to be in positions
2,4, and 6
There are {{{ 4!*3! = 144 }}} ways
for them to be seated