a. 7 fireflies are caught per minute.
b. 19 fireflies were already caught prior to the contest starting.
a.
Looking at the equations (3m + 13) and (4m + 6) where m is equal to the number of minutes since the contest began, it's obvious that there are 3+4 = 7 fireflies caught per minute.
b.
One again, look at the two equations. Or for that matter, calculate them both and add the results for m=0 (the moment the contest began). And upon doing so, you'll see that 13 + 6 = 19 fireflies were caught prior to the competition starting.
