A car is crossing a 20km long bridge. The bridge can support at most 1500kg of weight over it. If somehow, the weight on the bridge becomes more than that, it will break.

Now, the weight of the car is exactly 1500kg. At the midway, a bird comes and sits on the roof of the car. This bird weighs exactly 200 gram.
Can you tell if the bridge breaks at this point or not?

The bridge will not break.
This is because when the bridge reaches the mid-point, it would have traveled 10km. While traveling 10km, the car would have used more than 200 grams of fuel. Thus, the weight of bird will not add much to the existing weight.