Answer:
0.0083 = 0.83% probability that the boys will stand in alphabetical order from left to right in the picture
Explanation:
Probability:
A probability is given by the number of desired outcomes divided by the number of total outcomes.
Arrangments of x elements:
The total number of arrangments of x elements is given by:

Desired outcomes:
Standing in alphabetical order, so only 1 possible outcome, which means that

Total outcomes:
Arrangments of 5 people, so

Probability:

0.0083 = 0.83% probability that the boys will stand in alphabetical order from left to right in the picture