Answer:
1. Option 2:150,30,6,6/56/25
2.Option 1
3.I can't see the no.3 question clearly. I see the question as a subscript n=(n+3)^1/n+3 so here is the answer:
The five terms sequence:
n=0;a subscript 0=1(not very sure if this one is involved)
a subscript 1=1
a subscript 2=1
a subscript 3=1
a subscript 4=1
a subscript 5=1