Difficulty: Medium
Correct Answer: Rs. 2400
Explanation:
Given data
Concept / Approach
Step-by-step calculation
2a + 4b = 1600 … (1)a + 6b = 1600 … (2)From (2): a = 1600 − 6b.Substitute in (1): 2(1600 − 6b) + 4b = 1600 ⇒ 3200 − 12b + 4b = 1600 ⇒ −8b = −1600 ⇒ b = 200.Then a = 1600 − 6×200 = 400.Cost of 12 shirts = 12 × 200 = Rs. 2400.
Verification
Check (1): 2×400 + 4×200 = 800 + 800 = 1600 ✔; (2): 400 + 1200 = 1600 ✔.
Common pitfalls
Final Answer
Rs. 2400.
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