Answer: 45
Step-by-step explanation:
Ok, Kid 1 can meet other 9 kids, so we have 9 handshaks.
Kid 2 can also meet other 9 kids, but he already meet kid 1, so we are not counting that handshake, this means that now we have 8 handshakes.
Kid 3 can also meet 9 kids, but we already counted the handshake with kid 1 and kid 2, so here we have other 7 andshakes.
And so on, so we have a total of:
9 + 8 + 7 + 6 + 5 + 4 +3 + 2 + 1 = 45 handshakes in total.
