Set 16: Linear Functions (Advanced)

Explanation

Answer: A

Plan A costs $30/month + $0.05/text. Plan B costs $10/month + $0.15/text. For what number of texts are the costs the same?

$200$

✓ Correct

$100$

$300$

$150$

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Equate costs. 1. Plan A: $30+ 0.05 x$ . 2. Plan B: $10+ 0.15 x$ . 3. Equate: $30+ 0.05 x = 10 + 0.15 x$ . 4. Solve: Subtract $10\rightarrow 20 = 0.10 x$ . Divide by $0.10\rightarrow x = 200$ . Strategic Tip: The difference in base cost divided by difference in rate gives the break-even point. Choice B is incorrect. Choice C is incorrect. Choice D is incorrect.

Key Steps:

•

The correct answer is $200$

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.

← Previous Next →

🎯 Keep Practicing!

Master all sections for your best SAT score

📚Reading & Writing→📖Vocabulary→