Answer:
Alex has 110 shells, Benji has 132 shells and Carmen has 66 shells.
Step-by-step explanation:
The total number of shells gotten by Alex, Benji and Carmen is 308.
Let the number of shells Alex has be A, let the number of shells Benji has be B and let the number of shells Carmen has be C.
=> A + B + C = 308
Benji has 20% more shells than Alex, this means that we add 20% of Alex's shells to the number of shells Alex already has to get the number of shells that Benji has:
B = (20% of A) + A =
Carmen has 40% fewer shells than Alex, that means that we subtract 40% of Alex's shells from the number of shells Alex already has to get the number of shells that Carmen has::
C = A - (40% of A) =
Replacing B and C in the initial equation, we have that:
A + 1.2A + 0.6A = 308
=> 2.8A = 308
A = 308 / 2.8 = 110
∴ B = 1.2 * 110 = 132
and C = 0.6 * 110 = 66
Therefore, Alex has 110 shells, Benji has 132 shells and Carmen has 66 shells.