Suppose 6 boys and 4 girls sit together in a row in random o

Suppose 6 boys and 4 girls sit together in a row in random order.

(a) What is the probability that all the girls sit together and all the boys sit together (i.e., there is no boy sitting between two girls and no girl sitting between two boys)?

(b) What is the probability that no two girls sit together? [Hint: figure out how many ways 4 girls can be interleaved between 6 boys.]