Question 1109046
{{{x}}}= number of further consecutive heads leading to {{{"70%"}}} heads.
Once those {{{x}}} further throws showing heads are done,
the total number of throws will be {{{200+x}}} :
the total number of heads will be {{{110+x}}} ,
and the ratio of heads to total throws will be
{{{"70%"=70/100=0.7}}} .
Then,
{{{(110+x)/(200+x)=0.7}}}
{{{110+x=0.7(200+x)}}}
{{{110+x=140+0.7x}}}
{{{x-0.7x=140-110}}}
{{{0.3x=30}}}
{{{x=30/0.3}}}
{{{x=highlight(100)}}}