📌 Core Concept
We are given a system of linear equations based on the total number of shares and their respective values. The governing formula is:
Total Value=(Number of Shares×Price per Share) for each stock 🔢 Step-by-Step Solution
1
Calculate the value of stock A:
Number of shares of A = 10
Price per share of A = 120
Value of A = 10 × 120 = 1200$ rupees
2
Set up equations for stocks B and C:
Let
x be the number of shares of B.
Let
y be the number of shares of C.
Total shares of B and C:
x+y=20
Total value of B and C:
90x+150y=2100 (since total portfolio is 3300 and value of A is 1200)
3
Express
y in terms of
x:
4
Substitute
y into the value equation:
90x+150(20−x)=2100
Expand:
90x+3000−150x=2100
Combine like terms: - 60x + 3000 = 2100$
Solve for
x: - 60x = -900 ⇒ x = 15$
⚡ 30-Second Shortcut
Since the total shares of B and C are 20, and the total value is 2100, the average price per share is 105.
Stock B is 90, which is 15 less than 105, and stock C is 150, which is 45 more than 105.
Let the number of B shares be
x. The total deviation is - 15x + 45(20 - x) = 0$.
Simplify: - 15x + 900 - 45x = 0 ⇒ -60x = -900 ⇒ x = 15$.
🎯 Final Answer
Correct Answer: 15