Question 949243

The formula for calculating simple interest is 
{{{I=prt}}}, where {{{I }}}is the amount of interest, {{{p}}} is the amount invested, {{{r }}}is the annual rate of interest, and {{{t}}} is the time in years. 

Suppose that you invested ${{{1200}}} for a period of six years and earned ${{{396}}} simple interest. What was the annual rate of interest? 

given:

${{{I=396}}}
${{{p=1200}}} 
{{{t=6}}}

find {{{r }}}

{{{I=prt}}} .......plug in given values

{{{396=1200*r*6}}}.....solve for {{{r}}}

{{{396=7200*r}}}

{{{396/7200=r}}}

{{{r=0.055}}} or  {{{r=5.5}}}%


so, your answer is option d. {{{5.5}}}%