8

Set 1: Systems of Equations (Advanced)

Explanation

Answer: C

A gym charges $50 for a monthly membership and $5 per training session. Another gym charges $30 per month and $10 per session. After how many sessions in a month do both gyms cost the same?

A.

3 sessions

B.

5 sessions

C.

4 sessions

✓ Correct
D.

6 sessions

Detailed Explanation

Choice C is correct. Choice C is the correct answer. Let ss be the number of sessions. Set up equations for total cost at each gym. Gym 1: C1=50+5sC_1 = 50 + 5 s Gym 2: C2=30+10sC_2 = 30 + 10 s Set equal (cost is the same): $$$50+ 5 s = 30 + 10 s5030=10s5s50- 30 = 10 s - 5 s20= 5 ss = 4$$ Solution: 4 sessions Verification: - Gym 1: $$50+ 5(4) = 70$$ - Gym 2: $$30+ 10(4) = 70$$ ✓ Strategic Tip: "Break-even" problems ask where two expressions are equal. Choice A is incorrect because at 3 sessions: Gym 1 = 65, Gym 2 = 60 dollars (not equal). Choice B is incorrect because at 5 sessions: Gym 1 = 75,Gym2=80dollars(notequal).ChoiceDisincorrectbecauseat6sessions:Gym1=75, Gym 2 = 80 dollars (not equal). Choice D is incorrect because at 6 sessions: Gym 1 = 80, Gym 2 = 90 dollars (not equal).

Key Steps:

The correct answer is 4 sessions

Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
B: Choice B 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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