If the doubling time of a state's population is 42 years, how long does it take for the population to increase by a factor of 16?

2 answers

doublexdoublexdoublexdouble=16
So would your doublexdoublexdoublexdouble=16

be 2 x 2 x 2 x 2= 16??? I am a liitle confused on why you used double?