answer thos ans explain please

13. The semaphore code enables messages to be exchanged between people who can see each other. Each person has two flags, each of which can be displayed in one of eight possible positions. The two flags cannot occupy the same position. How many symbols can be encoded in this way, remembering that the coding function must be an injection? BBBBB, Sell SSSSS. If the following messages are received, which instruction is more likely to have been sent in each case? BBBSBSBSBSSSSSB