Question 117114
a = number of adults
c = number of children
{{{20a + 5c = 416}}}
{{{a + c = 31}}}
{{{a = 31 - c}}}
{{{20(31 - c) + 5c = 416}}}
{{{620 - 20c + 5c = 416}}}
{{{15c = 620 - 416}}}
{{{15c = 204}}}
{{{c = 13.6}}}
The closest answer is c. 13
If the answer is 13 children, and {{{a + c = 31}}}
{{{a = 31 - 13}}}
{{{a = 18}}} and
{{{20a + 5c = 416}}}
{{{20*18 + 5*13 = 416}}}
{{{360 + 65 = 416}}}
{{{425 = 416}}} obviously not true
So, they either miscounted their receipts, undercharged somebody,
or $9 got lost or stolen!!! But c. is still closest answer