A) If Mohit takes 20 hours,
Both of them took = \(15\times\frac{20}{ 15}+20\)
= \(\frac{300}{35}\) hours
So, this statement is enough to answer the question.
B) Since number of hours is inversely proportional to amount of work done.
So, Since Sanjay's working hours is given and Mohit's amount of work is given, we can find out the no. of
hours taken by Mohit.
\(\Rightarrow\;\)Work ratio of Sanjay and Mohit = \(4:3\)
\(\Rightarrow\;\)No. of hours required ratio = \(15:x\)
So, inverse ratio
\(\Rightarrow\;\)\(\frac{4}{3} = \frac{x}{15}\)
\(\Rightarrow\;\)\(x = 20\)
Hence, we can find number of hours taken by Mohit from individual sentences.
The correct option is (D): Each statement is sufficient by itself to answer the question asked.