Structural Calculations

Hello, I am a civil engineer and I have a structural assignment due tomorrow about solid timber joists and concrete slab. My friend also has the same exact assignment due tomorrow as well. We just have different values for A and B that are shown in figures 2 and 3. We should have the same method just different results in numbers. You could view the brief attached as well as the values for A, B, and C for both of us.