Answer this riddle: You measure my life in hours and I serve you by expiring. I’m quick when I’m thin and slow when I’m fat. The wind is my enemy.

A candle.

Explanation:

A candle can be defined as a cylindrical block of wax (tallow) with an embedded wick that burns when lit by fire.

The duration of time in seconds, minutes or hours a candle takes to burn depicts the life of the candle. Since candles are made up of wax, as they are being burned there is a gradual reduction in its length (to every action, there is an equal but opposite reaction) i.e it serves you by expiring.

The rate at which a candle burn is directly proportional to its width i.e it burns quickly if it is thin and slowly if it is fat. Like every source of fire, it can be extinguished by a wind. Thus, the wind is an enemy to a candle.

the answer is:

magna carta

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