Well, if you know it grinds 2/7lbs of spices in 1/3 of a second, you need to find how many lbs it can grind in 1 second. You can do this by multiplying both sides by 3: 27=13 27×3=67 13×3=1 Therefore, 67=1 The machine grinds 6/7 lbs of spices per second. Hope this helped!