The firms A, B and C saw rise of 15%, 6% and 9% respectively in 2012 from 2011. Whose revenue was least in 2011?

Firm A, B and C have a revenue of 2350, 4760 and 3870 crores, respectively in 2012.

So, calculating their revenues in 2011

Firm A - Saw a 15% rise

So, Firm A's 2011 revenue is $$\dfrac{2350}{\left(1+\dfrac{15}{100}\right)}=\dfrac{2350}{1.15}=2043.5$$ crores

Firm B - Saw a 6% rise

So, Firm B's 2011 revenue is $$\dfrac{4760}{\left(1+\dfrac{6}{100}\right)}=\dfrac{4760}{1.06}=4490.5$$ crores

Firm C - Saw a 9% rise

So, Firm C's 2011 revenue is $$\dfrac{3870}{\left(1+\dfrac{9}{100}\right)}=\dfrac{3870}{1.09}=3550.5$$ crores

Hence, the least revenue is of Firm A at 2043.5 crores.