At an Inflation Rate of 9 Percent, the Purchasing Power

Multiple Choice

At an inflation rate of 9 percent, the purchasing power of R1 would be cut in half in 8.04 years.How long to the nearest year would it take the purchasing power of R1 to be cut in half if the inflation rate were only 4%?

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