Instruct: What's the average L/km combines when the L/100km Urban is 13.9, the mpg-UK combined is more than 28.5 and the mpg-UK extra urban is less than 38.7?
Output: SELECT AVG L/100km Combined FROM table WHERE L/100km Urban (Cold) = 13.9 AND mpg-UK Combined > 28.5 AND mpg-UK Extra-Urban < 38.7