₹21,000 is divided among A, B and C in such a way that the shares of A and B are in the ratio 2 : 3, and those of B and C are in the ratio 4 : 5. The share of B is:

Given, 

Ratio of A : B = 2 : 3

i.e; $$\frac{A}{B}=\frac{2}{3}$$

Ratio of B : C = 4 : 5

i.e; $$\frac{B}{D}=\frac{4}{5}$$

now ,

$$\frac{A}{B}=\frac{2}{3}\times\ \frac{4}{4}=\frac{8}{12}$$

 $$\frac{B}{D}=\frac{4}{5}\times\ \frac{3}{3}=\frac{12}{15}$$

Therefore, 

A : B : C = 8 : 12 : 15

Let the ratios are 8x, 12x and 15x

According to question, 

8x + 12x + 15x = 21000

35x = 21000

x = $$\frac{21000}{35}$$

Share of B = $$\frac{21000}{35}\times\ 12=₹7200$$

Hence, Option C is correct.