Chayei Sarah: Eliezer Gives Gold to Rivka

After Rivka was finished watering the camels, Eliezer gave her a gold nose ring weighing ½ shekel and two gold bracelets weighing 10 shekels each [Kaplan: the Living Torah, Bereishis  24:22].

Question: How many shekels of gold did Rivka receive? 

Answer: .5 + (2 x 10) = 20.5 shekels