Task: Question Answering
Input (English): Problem: jack rode his bicycle at an average speed of 5 mph for some time and then at an average speed of 15 mph for the rest of the journey . if he made no stops during the trip , and his average speed for the entire journey was 10 miles per hour , for what fraction of the total time did he ride at 15 mph ? 
Options: a ) 1 / 5 , b ) 1 / 3 , c ) 2 / 3 , d ) 2 / 5 , e ) 1 / 2
Output (English): e