Problem $5\mathrm{.}13($Time for a Lump Sum to Double$)$

How long will it take $$700$ to double if it earns the following rates? Compounding occurs once a year. Round your answers to two decimal places.

a$.6\%.$

year$($s$)$

b$.13\%.$

year$($s$)$

c$.21\%.$

year$($s$)$

d$.100\%.$

year$($s$)$