SOLUTION: On a fishing trip, Mariko caught 24 fish. She caught soem rockfish weighing about 2.5lbs EACH and some blue fish about 8lbs EACH. The total weight of fish was 137lbs. How many of e

Algebra ->  Systems-of-equations -> SOLUTION: On a fishing trip, Mariko caught 24 fish. She caught soem rockfish weighing about 2.5lbs EACH and some blue fish about 8lbs EACH. The total weight of fish was 137lbs. How many of e      Log On


   

Question 840397: On a fishing trip, Mariko caught 24 fish. She caught soem rockfish weighing about 2.5lbs EACH and some blue fish about 8lbs EACH. The total weight of fish was 137lbs. How many of each fish did she catch.
These need to be solved using systems of equations.
thank you!
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!

-
Added "EACH" because this is what you meant; that rockfish are 2.5 pounds per fish and blues are 8 pounds per fish.

r for rock fish count
b for blue fish count

highlight_green%28r%2Bb=24%29 accounts for fish count.
highlight_green%282.5r%2B8b=137%29 accounts for pounds of fish.
That is the system to solve for r and b.

Putting into whole coefficients, the pound account is highlight_green%285r%2B16b=274%29.

SYSTEM easier to use as
--------------------
r+b=24
--------------------
5r+16b=274
--------------------

Elimination Method without explanation:
5r%2B15b-%285r%2B5b%29=274-5%2A24
10b=274-120
10b=154
b=15.4 But we cannot really allow for nonwhole numbers of fish unless some practical reason would make this possible. highlight%28b=15%29;
recall in the description, "about 8 pounds", and "about 2.5 pounds".
-
Expect that highlight%28r=9%29 of the rock fish.