<u>Solar Energy & Wind Power.</u>
One of the main thing about renewable energy, it will never run out, and it saves you money.
500 mg in g :
1 g ----------- 1000 mg
? -------------- 500 mg
500 x 1 / 1000 => 0.5 g
total mass:
50 g + 0.5 g + 0.1 g => 50.6 g
hope this helps!