Answer: 20
Explanation:
We know that 100% of 80 is 80.
So, 50% (half, or divided by 2) of 80 is 40. 50% is only half of 100%, so divide that by 2.
So, 25% (quarter, or divided by 4) of 40 is 20. 25% is only half of 50%, so divide what you have into 2 again.
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25% x 4 = 100%
so, 20 x 4 = 80
I hope you get the logic.