The table given below shows the average number of articles (A, B and C) sold by Pesto company in three different months. It also shows the percentage of article A sold by Pesto company out of the total number of articles sold in these months. Table also reflects the total number of article C sold in these months. Read the table carefully and answer the following questions.

Months	Average number of articles sold	Percentage of article A sold	Total number of articles C sold
April	100	40%	100
May	120	30%	70
June	72	25%	80

If the price of each article at which articles A, B and C sold in the month of April are Rs. 10, Rs y and Rs. (y + 20) respectively, then the total revenue generated by selling these articles in the month of April is Rs. 4100. Find the value of 3y.

The correct answer is 15.

Step 1: Find the total number of articles sold in the month of April.
From the given table, the average number of three types of articles (A, B, and C) sold in April is 100.
Since there are 3 types of articles, we can calculate the total number of articles sold as follows:

$\text{Total articles sold in April}=\text{Average}\times 3=100\times 3=300$

Step 2: Calculate the number of individual articles (A, B, and C) sold in April.
- Article A: The table states that 40% of the total articles sold in April were Article A.

$\text{Number of Article A sold}=40\%\text{of}300=\frac{40}{100}\times 300=120$

- Article C: According to the table, the total number of Article C sold in April is 100.

- Article B: The remaining articles sold in April are Article B.

$\text{Number of Article B sold}=\text{Total articles}-(\text{Article A}+\text{Article C})$

$\text{Number of Article B sold}=300-(120+100)=300-220=80$

Step 3: Formulate the revenue equation for April.
We are given the selling prices of the articles in April:
- Selling price of Article A = Rs. 10
- Selling price of Article B = Rs. y
- Selling price of Article C = Rs. (y + 20)

The total revenue generated in April is Rs. 4100.
Total Revenue = (Number of A × Price of A) + (Number of B × Price of B) + (Number of C × Price of C)

$(120\times 10)+(80\times y)+(100\times (y+20\left)\right)=4100$

Step 4: Solve for y and compute 3y.
Expand and simplify the algebraic equation:

$1200+80y+100y+2000=4100$

$3200+180\mathrm{y<mo>=</mo><mn>4100</mn>}$

$180y=4100-3200$

$180y=900$

$y=\frac{900}{180}=5$

Now, calculate the value of 3y:

$3y=3\times 5=15$

Thus, the value of 3y is equal to 15.