I tried it as
(number of ways selecting 4 girls out of 5)(arranging them on their seats )(ways we can find four consecutive sear for these girls)(selecting 10 seats from the remaining 12 seats )(arranging students in these 10 seats)
$=(^5 _4)(4!)(4)(^{12}_{10})(10!)$ = $^{11}P_6(6!)(2)$
But the answer is not this