$\left( {x \times 5} \right) = \left( {0.75 \times 8} \right) \Rightarrow x = \left( {\frac{6}{5} = 1.20} \right)$

\begin{align} & \left( {\frac{A}{B}} \right) \times \left( {\frac{B}{C}} \right) = \left( {\frac{3}{4}} \right) \times \left( {\frac{{12}}{{13}}} \right) \cr & Or, \, \frac{A}{C} = \frac{{36}}{{52}} = 9:13 \cr\end{align}

Let the two positive numbers be 5x and 3x respectively.

According to question,

5x-3x = 10;

Or, x = 5.

Then numbers are 25 and 15.

Thus, their product = 25*15 = 375.

Let the shares of A, B, C and D be Rs. 5x, Rs. 2x, Rs. 4x and Rs. 3x respectively.

Then, 4x - 3x = 1000

⇒ x = 1000.

∴ B's share = Rs. 2x = Rs. (2 x 1000) = Rs. 2000.

\begin{align} & {\text{ }}a{\text{ }}:{\text{ }}b{\text{ }}:{\text{ }}c \cr & {\text{ }}3{\text{ }}:{\text{ }}4{\text{ }}:{\text{ }}7{\text{ }} \cr & \boxed{3x:4x:7x} \Rightarrow 14x \cr & \therefore a + b + c = 14x \cr & c = 7x \cr & \therefore \left( {a + b + c} \right):c \cr & = 14x:7x \cr & = 2:1 \cr\end{align}