Answer: It doubles
Step-by-step explanation:
Inflation erodes the value of a currency thereby reducing the purchasing power that customers have as they will only be able to buy less gods and services for the same amount as before.
An increase in inflation is directly proportional to a decrease in purchasing power which means that if the inflation rate doubles, the decrease in purchasing power doubles as well.
For instance, if inflation is 10%, the value of a dollar becomes 0.9c. If Inflation doubles to 20%, the dollar goes to 0.8c. Meanwhile the purchasing power would have gone from $1 to 0.8c which would translate to a 20% decrease.