A retailer sold 2 houses at each $10000. On 1st house he got 30% profit and on 2nd house he loss 10% then find his net profit or loss?	Choose the most appropriate option
A) 15 %
B) 17 %
C) 21 %
D) 19 %
E) 25 %

Rationale: a = 30 % b = - 10 % profit % = 30 - 10 + ( - 300 / 100 ) = 17 % answer is b
Answer: B