Linear Programming Problem

Kunz manufactures two products that are used in the heavy equipment industry. Both products require maunfacturing operations in 2 different departments (A and B). The following are the production times (in hours) and profit contributions for the two products:

Product Profit/Unit Dept A (in hours) Dept B (in hours)

1 $25 6 12

2 $20 8 10

For the coming period, Kunz has a total of 900 hours of labour that can be allocated to either of the two departments. Formulate an LP to maximize the numbers of hours to allocate per department and total contribution to profit.

So I created 4 variables:

X1 - Hours of Product 1 in Dept A

X2 - Hours of Product 1 in Dept B

X3 - Hours of Product 2 in Dept A

X4 - Hours of Product 2 in Dept B

I formulated the following LP:

Max Z = 25(X1 + X2) + 20(X3 + X4)

s.t.

6X1 + 12X2 + 8X3 + 10X4 <=900

all variables => 0

Is my solution correct?