Final answer:
To determine the original cost of the laptop, divide the savings amount by the percentage discount (0.10 in this case). The original cost is $350.
Step-by-step explanation:
To find the original cost of the laptop, we need to determine the amount saved from the 10% off sale. If the savings amount is $35, we can set up the equation:
10% of the original cost = $35
To solve this equation, we can divide both sides by 0.10 (which is the decimal form of 10%).
Original cost = $35 ÷ 0.10 = $350
Therefore, the original cost of the laptop was $350 (option b).