Answer:
15
Step-by-step explanation:
Number of brown trout = 6
Number of lake trout = 18
Total number of trouts = 
Probability to catch a lake trout first time = 
As the fisherman let the trout go, so probability for the second time is =

Hence, the probability becomes=

= 
The probability to find the brown trout is 
as , 
= 
A) 12 40/30 is equal to 4/3. 4/3=16/x 4x =48. X=12
Okay so write it like this 27.50 thats the answer