Answer:
12 Granny Smith and 7 Gala apples (total 19 apples)
Explanation:
Let me put this equation first:
X: number of Granny Smith apples
(19-X): number of Gala apples
cos
t
=
X
⋅
0.25
+
(
19
−
X
)
⋅
0.30
5.10
=
0.25
X
+
5.70
−
0.30
X
5.10
−
5.70
=
−
0.05
X
−
0.60
=
−
0.05
X
and
X
=
12
Number of Granny Smith apples is 12.
The rest (19-12) is number of Gala apples. Number of Gala apples is 7.
This satisfies your equation.
Number of Granny Smith apples 12 and number of Gala apples is 7.
