Question

[NongDucCong]

mot hoc sinh lay 125 nhan voi 1 so co 2 chu so giong nhau,nhung khi nhan toi chu so thu 2 da vo y quen viet tich rieng thu 2 dich sang ben trai 1 chu so,nen tich so tim duoc la 500.Em hay tim thua so thu 2 cua phep tinh nhan