Question 66984
{{{c / (p/m) = (c+n) / (p/x)}}}
where x is the minutes when c+n children are eating
{{{cm/p = (c+n)x/p}}}
{{{cm = (c+n)x}}}
{{{x = cm / (c+n)}}} answer
try with numbers
c = 100
n = 20
m = 36
{{{x = cm / (c+n)}}}
{{{x = 100*36 / (100+20)}}}
{{{x = 3600 / 120}}}
{{{x = 30}}}