$$1+2+7=10$$，  $$1+3+6=10$$，  $$1+4+5=10$$，  $$2+3+5=10$$．  So the answer is $$\text{A}$$． 
How many ways are there of making a total of 10 using three different positive numbers? 
A) $$4$$ 
B) $$3$$ 
C) $$2$$ 
D) $$1$$ 
E) $$0$$ 