有幾題math 唔識，有冇人可以幫幫手 please?

There are 7 cups of different sizes.3 of them are green and 4 of them are blue
ai) find the number of ways of arranging the cups ina row if the leftmost and rightmost cups are of the same colour
aii )all the cups of the same colour are put next to each other
b)together with the 7 cups，6more green cups and 2 more blue cuos are put in a box， where all the 15cuos are of different sizes。7cups are randomly selected from the box and arranged in a row. Find the probability that 3 green cups and 4 blue cups are selected and all the cups of the same colour are put next to each other.