Three identical yellow balloons, two identical red balloons and two identical blue balloons are strung in a row to celebrate Shema's birthday. Calculate the number of arrangements if:
a. the balloon at each end is the same colour.
b. the yellow balloons are next to each other and the blue balloons are not next to each other.
a. the balloon at each end is the same colour.
b. the yellow balloons are next to each other and the blue balloons are not next to each other.