The are 6 girls and 5 boys standing in a queue. Amit is one of the boys and he always stands at the end of the queue. No two boys stand in consecutive positions. How many arrangements are possible?

6*5!*6p4

first arrange the girls =6!

there will be 7 positions for boys.

consider amir at 1st position. so remaining  boys in 6 posittions=6p4

now consider amir at last. so for remaining boys arrangement=6p4

so it will be 6!.2.6p4