Step 1: Historical context
Mahatma Gandhi had been in South Africa since 1893, where he fought against racial discrimination and developed his method of non-violent resistance, known as Satyagraha.
Step 2: Return to India
After gaining international recognition for his work in South Africa, Gandhi decided to return to India to continue his struggle for justice. He came back to India at the invitation of Gopal Krishna Gokhale, his political mentor.
Step 3: Exact date
Gandhi landed in Bombay (now Mumbai) on 9th January 1915. This date is now celebrated as Pravasi Bharatiya Divas (NRI Day) in India.
Step 4: Final Answer
Therefore, Mahatma Gandhi came back to India in January 1915.
\[
\boxed{\text{January 1915}}
\]
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.