一头牛可换5头猪,一头猪可换10只羊。现有羊100只,可换几头牛?5v-@4f0e0H
算式:提示-\.n/?;r.r*Q,M(v*M-o5v-@4f0e0H
答:可换)M(f,^:N0a(l(x3V.s-O,F's0e;P头牛。5v-@4f0e0H