At an Inflation Rate of 9 Percent,the Purchasing Power of $1

Multiple Choice

At an inflation rate of 9 percent,the purchasing power of $1 would be cut in half in 8.04 years.How long to the nearest year would it take the purchasing power of $1 to be cut in half if the inflation rate were only 4 percent?

A) 12 years
B) 15 years
C) 18 years
D) 20 years
E) 23 years