Task: Question Answering
Input (English): Problem: an enterprising businessman 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 20 th day of business , he earns an income of : 
Options: a ) rs 219 , b ) rs 220 , c ) rs 20 ² , d ) rs 20 , e ) rs 30
Output (English): a