pake caranya ya.. secepatnya

[tex]100 - (40 + 15 + 20) \\ 100 - 75 = 25\%(ayam) \\ \frac{40}{100} \times jumlah \: semua \: hewan = 80 \\ 40 \times jsh= 80 \times 100 \\ jsh = \frac{80 \times 100}{40} \\ jsh = 200 \\ jumlah \: ayam = \frac{25}{100} \times 200 = 50 \\ jumlah \: bebek = \frac{20}{100} \times 200 = 40 \\ selisih = 50 - 40 = 10(c)[/tex]

Maaf kalo salah, semoga membantu