Two numbers are such that the ratio between them is 4 : 7. If each is increased by 4, the ratio becomes 3 : 5. The lager number is ?

Answer: Option C

Let the numbers be 4x and 7x
Then,
$$\begin{array}{rl}& \iff \frac{4x+4}{7x+4}=\frac{3}{5}\\ & \iff 5\left(4x+4\right)=3\left(7x+4\right)\\ & \iff x=8\end{array}$$
∴ Larger number :
= 7x
= 7 × 8
= 56