If the investment of company A in 2007 and 2008 were equal, what is the difference between the profit earned in the two years if the income in 2008 was Rs. 24 lakh?

Let the investment of A in 2008 be Rs. $$x$$. Then,
$$\eqalign{ & \left(\frac{160}{100}\times x\right) = 24\text{ lakh} \cr & \Rightarrow x = \left(24\times\frac{5}{8}\right) \text{lakh} \cr & \Rightarrow x = 15 \text{ lakh} \cr} $$
∴ Investment of A in 2008 = 15 lakh
Profit of A in 2008
= Rs. (24 - 15) lakh
= Rs. 9 lakh
Investment of A in 2007
= Investment of A in 2008
= Rs. 15 lakh
Profit of A in 2007
$$\eqalign{ & =\text{Rs.} \left(\frac{45}{100}\times15\text{ lakh}\right) \cr & =\text{Rs.} \frac{27}{4}\text{ lakh} \cr & =\text{Rs. 6.75 lakh} \cr} $$
Difference between the profits of A in 2007 and 2008
= Rs. (9 - 6.75) lakh
= Rs. 2.25 lakh