You can help me please OOOChEN is NECESSARY! I will be glad if you are able to help me at least with one task! And in advance thanks!

104
The 1st - x, the 2nd - the 6th x +6th =42 of the 7th =42 x =42:7 x the =6-first the 6*6=36-second of the girl - x, boys x +6 x + x +6=30 2 =30-6 2 =24 x =24:2 x =12-girls of 12+6=18 boys 12+18=30
10
Answer add