You have a coupon for an additional 25% off the price of any sale item at a store. the store has put a robotics kit on sale for 15% off the original price of $40. what is the price of the robotics kit after both discounts.

So there is an easy way to find discounts or markdowns with just one multiplication set, by subtracting the percent from 100. So for this, 100-15= 85, so it would be 85 percent. We can even check to make sure.
40×.85=34=40-40×.15= 34
Now we have 34, let's do the second discount.
34×.75=25.5=34-34×.25=25.5
So it would be $25.50 after both of the discounts.

The answer is 109 times per second