10
Answer: BSet 6: Systems of Equations (Intermediate)
Explanation
Jessica splits $15,000 between two investments. One pays 5% annually, the other 8% annually. After one year, total interest is $990. How much was invested at 5%?
A.
\6,000$
B.✓ Correct
\7,000$
C.
\8,000$
D.
\9,000$
Detailed Explanation
Choice B is correct. Choice B is the correct answer. Let = amount at 5% and = amount at 8%. System: Step 1: From first: Step 2: Substitute: $$$0.05x + 0.08(15000 - x) = 9900.05x + 1200 - 0.08 x = 990$-0.03 x = -210x = 7000 Solution: $7,000 at 5% (and $8,000 at 8%) Verification: ✓ Strategic Tip: Investment problems: Principal × Rate = Interest. Other choices fail verification.
Key Steps:
•
The correct answer is \7,000$
Why others are wrong:
A: Choice A 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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