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1. The sum of two numbers is 22 and the sum of their squares is 404, then the product of two numbers is -
- A. 40
- B. 40
- C. 40
- D. 40
Answer: Option A
Explanation:
ATQ,
x + y = 22 ... (i)
x2 + y2 = 404 ... (ii)
Therefore, (x + y)2 = x2 + y2 + 2xy
(22)2 = 404 + 2xy
484 = 404 + 2xy
Or, 2xy = 80
Or, xy = 40
x + y = 22 ... (i)
x2 + y2 = 404 ... (ii)
Therefore, (x + y)2 = x2 + y2 + 2xy
(22)2 = 404 + 2xy
484 = 404 + 2xy
Or, 2xy = 80
Or, xy = 40
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