To find the sale price of the laptop, we first calculate the discount and then subtract it from the regular price.

Step-by-step solution:

1. Regular price: $850
2. Discount: 30% of $850 $\text{Discount} = 0.30 \times 850 = 255$
3. Sale price: Regular price minus the discount $\text{Sale price} = 850 - 255 = 595$

Thus, the sale price of the laptop is $595.

Would you like more details or explanations? Here are some related questions:

1. If the student had a 40% discount instead, what would the sale price be?
2. What would the total be with a 5% sales tax added to the sale price?
3. How much more would the student pay if the discount was only 20%?
4. What is the percentage discount if the student paid $600 for the laptop?
5. How much would the student save if the regular price was $900 with a 30% discount?

Tip: Always multiply the percentage (in decimal form) by the original price to find the discount.