Question 960412
{{{ 2*1360 = 2720 }}}
Let {{{ n }}} = the number of years it
takes for $1360 to double
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{{{ 2720 = 1360*( 1 + .1 )^n }}}
{{{ 2720 = 1360*(1.1)^n }}}
Take the log of both sides
{{{ log( 2720 ) = log( 1360 ) + log( (1.1)^n ) }}}
{{{ log( 2720 ) = log( 1360 ) + n*log(( 1.1 )) }}}
{{{ 3.4346 = 3.1335 + n*.04139 }}}
{{{ n*.04139 = .3011}}}
{{{ n = .3011 / .04139 }}}
{{{ n = 7.2747 }}}
It would take about 7 years and 4 months
check:
{{{ 2720 = 1360*( 1 + .1 )^n }}}
{{{ 2720 = 1360*( 1 + .1 )^7.2747 }}}
{{{ 2720 = 1360*2.0004 }}}
{{{ 2720 = 2720.544 }}}
error due to rounding off
close enough to get the year and month