cau hoi IQ
Saturday, March 7, 2009 9:45:00 PM
Co 3 thang di uong cafe, ti'nh tien $25. 3 thang hu`ng tien, moi thang bo $10 (vay la tong cong $3o). Ong chu thoi lai $5. Boa $2, 3 thang kia moi thang giu lai $1. Vay ti'nh ra 3 thang kia moi thang hu`ng ra $9.( 9x3=27), cong voi $2 boa là $29. Con $1 kia dau?









