In a class of 19 students, 7 boys failed in a test. Those who passed scored 12, 15, 17, 15, 16, 15, 19, 19, 17, 18, 18 and 19 marks. The median score of the 19 students in the class is

Clearly, median score = score of $\left(\frac{19+1}{2}\right)$
=10th student
Since, seven boys are failed out of 19, therefore, according to given information, these score will be less than 12
Now, on arranging these scores in ascending order, we get score of 10^th student is 15.