The Rule of 70 States That

Multiple Choice

The rule of 70 states that:

A) if y_t grows at a rate of g percent per year, then the number of years it takes y_t to double is approximately equal to 70/g
B) if y_t grows at a rate of g percent per year, then the number of years it takes y_t to double is exactly equal to 70/g
C) if y_t grows at a rate of g percent per year, then the number of years it takes y_t to double is approximately equal to g/70
D) if y_t grows at a rate of g percent per year, then the number of years it takes y_t to triple is approximately equal to 70/g
E) if y_t grows at a rate of g percent per year, then the number of years it takes y_t to double is approximately equal to 70/(1 + g)