Hi. All you have to do is divide 100 by 150 which is 0.6666.... and multiply it by the new variable which is “100 lakhs”
(100/150) X 100 = %66.66
Finally subtract the new percentage by 100, and get your final result.
100-66.66 = %33.33
*The percentage of illiterate people decreased by %33.33 in the past 10 years.
I hope this answer helps :)