###Human: Sam bought a heavy safe with a combination lock. There were four rows with twenty gold bars per row arranged in the safe. If each gold bar is worth $20000, calculate the total worth of the gold bars in the safe., ### Assistant: If there were four rows of twenty gold bars arranged in the safe, the total number of bars in the safe is 4*20 = 80 bars.
Since each gold bar is worth $20000, the 80 bars are worth 80*$20000 = $1,600,000 
 So the answer is :  1600000