Carl bought 19 apples or 2 different varieties to make pies. The total cost of apples was $51.00. Granny Smith apples cost $3.00 per pound and Gala apples cost $2.50 per pound. How man pounds of Granny apples did Carl buy?

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.