The captains of five cricket teams, including India and Australia, are lined up randomly
next to one other for a group photo. What is the probability that the captains of India and
Australia will stand next to each other?
๐ฅ Video solution / Text Solution of this question is given below:
Treat IndiaโAustralia as one block. Then we have $4!$ ways to arrange the block with the other 3 captains, and $2$ orders inside the block (IA or AI). Favorable $=2\cdot4!=48$; total $=5!=120$.