38人一圈,每人想个数告诉两旁人,他将两旁人告诉的

38人一圈,每人想个数告诉两旁人,他将两旁人告诉的平均数报出来是1,2.38,请问报1的同学想的是几

1个回答

2x1+x3+x37-(x3+x5)+(x5+x7)-.+(x33+x35)-(x35+x37)
=2x1+x3+x37-8+12-16+20-24+28-32+36-40+44-48+52-56+60-64+68-72-(x3+x37)
=2x1+32-72
=2x1-40=(x1+x3)+(x37+x1)=2*2+2*38=80
∴2x1=120 => x1=60 报1的同学想的是60