Manisha ranked sixteenth from the top and twenty ninth from the bottom among those who passed an examination. Six boys did not participate in the competition and five failed in it. How many boys were there in the class ?

Answer: D. 55
Number of boys who passed = (15 + 1 + 28) = 44. .'. Total number of boys in the class = 44 + 6 + 5 = 55.