The original price is 100% of the price. If the price is marked 60% off, then you pay 40% of the original price.
An item costs x dollars.
With the 60% off discount, it now costs 40% of x, or 0.4x.
Now you apply a 30% discount.
For the second discount, consider the price 0.4x to be the new original price. If the price is now discounted 30%, you will pay 70% of the new original price.
Start with 0.4x.
Now calculate 70% of 0.4x.
70% of 0.4x = 0.70 * 0.4x = 0.28x
After applying the 60% discount and the 30% discount, the item that originally cost x now costs 0.28x. 0.28x is the same as 28% of x. The amount you pay is 28% of the original price.
Answer: 28%