How to attach the element into correct index

I HAVE VECTOR A = [0,540]

B = [60,600,15]

how to attach B(3) as A(3) ? //output should be A = [0,540,15]

how to attach B(1) as A(1) ? //output should be A = [60,600,15]

Answer 1

[Fangjun Jiang]

A=[A,B(3)]
A(1,:)=B(1,:)