Answer:
200000
Step-by-step explanation:
The boat licenses are strings of six elements. Let's count the number of ways of constructing such string with the given conditions.
There are 2 ways of choosing the first character of the string (A or M). The second character can be any digit, so there are 10 possible choices. The third character is also any digit, so it can be chosen in 10 ways. Similarly, the fourth character can be chosen in 10 ways, and the fifth character can be chosen in 10 ways.
By the product rule there are 2×10×10×10×10×10=2×10^5=200000 ways to choose all the characters. Every choice of characters becomes a unique string (boat license) thus the number of avaliable boat licenses is 200000.s
