Question 1179258
c, child ticket price
a, adult ticket price

{{{system(5c+6a=112.5,4c+8a=130)}}}


{{{(1/2)*E2}}}:
{{{system(5c+6a=112.5,2c+4a=65)}}}


{{{5*E2}}}
{{{2*E1}}}:
{{{system(10c+12a=225,10c+20a=325)}}}


{{{E2-E1}}}:
{{{8a=100}}}

{{{highlight(a=12.5)}}}


and then
{{{c=(112.5-6*12.5)/5}}}

{{{highlight(c=7.5)}}}