You think that if you drive from 30 mph to 40 mph, you’ll save a lot of time—more than if you go from 60 mph to 70 mph on the same trip. But actually, increasing speed when you’re already going fast saves less time than when you're going slower. Or you’re walking slowly to work and decide to jog a bit faster to arrive early. You feel like you’ve gained a lot of extra minutes—but it’s not as much as you think. That’s the time-saving bias at work. Take the quiz to see why our intuition about speed and time often tricks us!