A owner of a mart earns an income of Re 1 on the first day of his business. On every subsequent day, he earns an income which is just double of that made on the previous day. On the 10th day of business, he earns an income of: Choose the most appropriate option:
A) 18	B) 21	C) 22	D) 20	E) 30

Rationale: 2 nd day he earns = 2 ( 2 – 1 ) 3 rd day he earns = 2 ( 3 – 1 ) on 10 th day he earns 2 ( 10 - 1 ) = 18 rupees answer : a
Answer: A