Answer: 2004 and 2009

Explanation:
from the given line graph, it is clear that the difference between the
=> Percentage of candidates qualified to appeared was maximum for the years 2004 and 2009 as 2004 has the minimum percentage while 2009 has the maximum percentage.

Answer: Data inadequate 

Explanation:
we can’t determine the actual number of qualified candidates as we
=> Don’t know the number of appeared students

Answer: 26500

Explanation:
let number of candidates appeared in 2008 be x,
=> Then, 80% of x = 21200
=> x = 21200 x 100/80 = 26500

Answer: Data inadequate

Explanation:
Data is inadequate to answer this question as we don’t
=> Know the number of candidates appeared in 2006 and in 2007, separately.

Answer: 20500

Explanation:
Number of candidates appeared in 2009 = 26500
=>Therefore, number of candidates qualified in 2009
=> 80% of 26500 = 21200
=> Number of candidates qualified in 2010
=> 33500 – 21200 = 12300
=> Now, let the number of candidates appeared in 2010 be x.
=> Then, 60% of x = 12300
x = 12300 / 60 x 100 = 20500