Hari can do 25% of a work in 5 days. How many days will it take him to do the work twenty times bigger than this?

Correct option is D

Given
Time for 25% work = 5 days

Solution
Time for $$100\% (1 full\ work) = \frac{5}{25\%} = 20\ days$$​​
Work required = 20 times the original work
Time required = 20 times 20 days = 400 days

Final Answer
So the correct answer is (d)