Answer:
The c statement is not true.
Explanation:
We need to check every statement to determine which one is false.
a. The old tax rate was 6% and the new one is 18%. The difference between the new and the old one will give us how much it's been increased. So 18-6=12, meaning the tax has increased 12%, so this statement is true.
b. If we multiply by 3 the old tax rate we get 6x3=18, which is the same as the new tax rate, so this statement is also true.
c. Increasing the tax rate 100% would mean multiplying by 2, since 100% is the same as the number, so adding that to the same number would double the amount. By the same logic, increasing it 200% would be the same as multiplying it by 3, and by 4 with a 300% increase. Since we already determined that the new tax was 3 times the old one, this statement is false, and the d. statement is true.