This week laptops are 25 percent off if a laptop cost $340 what is it's sale price

The sale price is 255 dollars.
To get the answer you find out that ten percent of 340 is 34 dollars. then you double the percentage which brings you to 68 dollars. but you still have 5 percent left over. Half of the ten percent is 17 dollars. finally you add 68 plus 17 which gives you 84 dollars. Lastly subtract 84 dollars from 340 which gives you 255

Hope this helps! :)