Yes, both the ball will touch the ground at the same time.
Both the balls are being attracted by the earth and the rate of acceleration is same, i.e, g=9.8 meter/second (square). As g doesn't depend on the mass, both the balls will hit the ground at the same. [Applicable formula: s=ut+1/2gt(square); here s is same, u is same=0, g is same=9.8. So, t will also be same.]
Please refer to Galileo's famous experiment at Pisa's leaning tower. He did the same experiment.
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