Answer
55 children, 332 adults
Work Step by Step
$x$ adults at 6.8
$387-x$ children at 3.4
387 total people for total of 2444.60
$6.8*x+3.4*(387-x)=2444.60$
$6.8x+1315.8-3.4x=2444.6$
$3.4x = 1128.8$
$3.4x/3.4 = 1128.8/3.4$
$x=332$
$387-332 = 55$