Task: Question Answering
Input (English): Problem: a sports retailer ordered white and yellow tennis balls in equal number but the dispatch clerk of the tennis ball company erred and dispatched 20 extra yellow balls and making ratio of white balls to yellow balls 8 / 13 . how many tennis balls did the retailer order originally . 
Options: a ) 64 , b ) 130 , c ) 140 , d ) 160 , e ) 120
Output (English): a