Set 4: Linear Equations

Explanation

Answer: A

Total $10,000 invested. Part at 5%, part at 8%. Total interest$ 620. How much at 8%?

Amount at 8%?

$4000

✓ Correct

$8000

$6000

$2000

Detailed Explanation

Choice A is correct. Let x = amount at 8%. (10000-x) at 5%. 0.08 x + 0.05(10000-x) = 620. 0.08 x + 500 - 0.05 x = 620. 0.03 x = 120. x = 4000.

Key Steps:

•

The correct answer is $4000

Why others are wrong:

B: Choice B is incorrect and may result from a calculation error.

C: Choice C is incorrect and may result from a calculation error.

D: Choice D is incorrect and may result from a calculation error.

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