Answer :
( 1 / 4 ) * 30000 =7500 words in 1 / 6 of an hour ;
2 * 7500 words in 2 * ( 1 / 6 ) of an hour => 15000 in 1 / 3 of an hour ;
2 * 15000 words in 2 / 3 of an hour => 30000 words in 40 minutes ;
2 * 7500 words in 2 * ( 1 / 6 ) of an hour => 15000 in 1 / 3 of an hour ;
2 * 15000 words in 2 / 3 of an hour => 30000 words in 40 minutes ;