Trung binh cong cua 4 so la 32.Lay so thu nhat cong voi 3,so thu hai tru di 3,so thu 3 nhan voi 3,so thu 4 chia voi 3, thi duoc 3 so bang nhau.tim so be nhat trong 4 so do.
1. tbc cua 3 so la 19/60 .neu gap so thu nhat len 4 lan thi tbc cua chung se la 13/20 .tim 3 so , biet so thu hai hon so thu ba 1/6
2. trong mot phep tru co tong so bi tru ,so tru va hieu la 1998.biet hieu so bang 4/5 so tru .hay tim so bi tru va so tru , hieu
cho bon so co tong bang 90 . neu đem so thu tu cong voi 2 , so thu 3 tru di 2 , so thu hai nhan voi 2 so thu nhat chia cho 2 m, thi duoc bon ket qua bang nhau . tim bon so
Cho 4 so co tong bang 45.Neu lay so thu nhat cong voi 2, so thu hai tru di 2, so thu ba nhan 2, so thu tu chia 2 thi duoc 4 ket qua bang nhau. Tim moi so do.
1.tim so bi chia trong phep chia cho 12 co thuong la 35 va so du la so le co 2chu so
2.hieu cua so lon nhat co 4 chu so khac nhau va so nho nhat co 4 chu sola bao nhieu
3.mot hinh chu nhat co chieu dai gap ruoi chieu rong. Neu moi chieu tang them 1m thi duoc hinh chu nhat moi co dien tich tang them 26m2. Tinh chu vi hinh chu nhat
4.trung binh cong cua 2 phan so bang 5/12. Phan so thu nhat hon phan so thu hai 1/6. Tim phan so thu nhat
5.tim y biet (5/7 - y) nhan 4/5 =7/10 + 1/2
6.hieu 2 so =1/3 so be.Tong 2 so la 63. Tim so be
tim mot so biet so do chia 3 cong 12 hoac nhan 3 tru 12 deu co ket qua bang nhau
Cho 3 so co tong la 321,95.neu dem so thu nhat nhan voi 3 so thu hai nhan voi 4 so thu ba nhan voi 5 thi duoc 3 so bang nhau. Tim 3 so do
choo 2 so co tong la 86,1va biet neu dem so thu nhat nhan voi 4 so thu 2 nhan voi 3 thi duoc ket qua bang nhau .Tim so thu nhat
o 1 nha may co 3 to cong nhan neu lay 20% so cong nhan o to 1 chia deu cho 2 to con lai tyhi so cong nhan o 3 to bang nhau neu to 1 co them 8 cong nhan thi so cong nhan cua to 1 bang tong so cong nhan cua 2 to kia hoi to 1 co ? cong nhan