Read the following information carefully and answer the questions given below. The information about three sellers who sold two types of rice, i.e., brown and white.

The quantity of white rice sold by all three seller is 230 kg. The quantity of brown rice sold by B is 20% more than the quantity of white rice sold by A. The quantity of white rice sold by B is 20 kg more than that of brown rice. The ratio of brown rice sold by A to B is 2:3. The average quantity of brown rice sold by all three sellers is 60 kg, and the total rice (white and brown) sold by C is 75 kg.

If the price of each kg of white rice sold by A is Rs 20 and the total revenue earned by A to sell all the quantity of rice (brown + white) is Rs 2580, then find the price of each kg of brown rice sold.

The correct answer is 18.

Let's break down the information step-by-step to find the quantities of rice sold by the sellers.

Let the sellers be A, B, and C.
Let $W_A$, $W_B$, and $W_C$ represent the quantities of white rice (in kg) sold by A, B, and C respectively.
Let $B_A$, $B_B$, and $B_C$ represent the quantities of brown rice (in kg) sold by A, B, and C respectively.

From the given data, we have the following equations:

1. The total quantity of white rice sold by all three sellers is 230 kg:
$W_A+W_B+W_C=230$

2. The quantity of brown rice sold by B is 20% more than the quantity of white rice sold by A:
$B_B=1.20\times W_A$

3. The quantity of white rice sold by B is 20 kg more than that of brown rice sold by B:
$W_B=B_B+20$

4. The ratio of brown rice sold by A to B is 2:3:
$\frac{B_A}{B_B}=\frac{2}{3}\Rightarrow B_A=\frac{2}{3}{B}_B$

Substituting $B_B=1.20W_A$ into the expression for $B_A$ gives:
$B_A=\frac{2}{3}\left(1.20W_A\right)=0.80W_A$

5. The average quantity of brown rice sold by all three sellers is 60 kg:
$\frac{B_A+B_B+B_C}{3}=60\Rightarrow B_A+B_B+B_C=180$

6. The total rice (white and brown) sold by C is 75 kg:
$W_C+B_C=75\Rightarrow B_C=75-W_C$

Now, let's substitute $B_C=75-W_C$ into the equation for the total brown rice:
$B_A+B_B+75-W_C=180$
$B_A+B_B-W_C=105$

From the total white rice equation, we can express $W_C$ as:
$W_C=230-W_A-W_B$

Substituting this back into our equation:
$B_A+B_B-(230-W_A-W_B)=105$
$B_A+B_B+W_A+W_B=335$

Now, express all variables in terms of $W_A$:
$B_A=0.8W_A$
$B_B=1.2W_A$
$W_B=B_B+20=1.2W_A+20$

Substitute these into the equation:
$0.8W_A+1.2W_A+W_A+(1.2W_A+20)=335$
$4.2W_A+20=335$
$4.2W_A=315$
$W_A=75\text{kg}$

Now we can calculate the quantity of brown rice sold by A ($B_A$):
$B_A=0.8\times 75=60\text{kg}$

Next, we calculate the revenue and price for seller A:
The price of white rice sold by A is Rs 20 per kg.
Revenue from white rice for A = $75\text{kg}\times \text{Rs}20=\text{Rs}1500$

The total revenue earned by A is Rs 2580.
Revenue from brown rice for A = $2580-1500=\text{Rs}1080$

The price of each kg of brown rice sold by A is:
$\text{Price}=\frac{1080}{60}=\text{Rs}18$