In this example, one get clear idea how to calculate reactions when a simply supported beam is having overhang on one side of the support.
Example
Calculate the reactions of simply supported beam with overhang on left side of support as shown in figure. 
Solution
Take moment about point C, for reaction R1 
\(\sum M_{c}\space = 0\)
Law of equilibrium says;
Clockwise moments = Counter clockwise moments
R1 x 4 = (200 x 4) x 2 + 600 x 6
4R1 = 1600 + 3600 = 5200
R1 = 1300 kg.
For reaction R2, consider upward forces are equal to downward forces.
\(\sum F_{V}\space = 0\)R1 + R2 = 600 + 200 x 4
1300 + R2 = 1400
R2 = 1400 – 1300
R2 = 100 kg.
