Tim 1 ps so bang 3/4 va biet neu lay tu so cua phan so do cong voi 5 thi duoc ps bang ps 4/5
tim 1 ps biet rang neu cong them 4 vao ts va giu nguyen ms thi ta duoc ps moi = 1 con neu giu nguyen ts va cong them 3 vao ms thi ta duoc ps moi = 1/2 ps do la
cho 3 phan so biet tbc cua no = 7phan 6 neu tang phan so thu nhat len 2 lan ,thi tbc cua chung = 41 phan 30 , neu tang ps thu hai len 2 lan thi tbc cua no = 13 phan 9 . tim ps be nhat trong 3 ps
cho mot ps co tong cua tu va mau la 4013 va mau hon tu la 1.Hay tim ps do ..Neu cong them 4455332 vao tu thi phai them vao mau bao nhieu de duoc gia tri ps khong doi.
tim mot ps biet neu chuyen 5 don vi tu mau len tu thi duoc ps =1/3.neu chuyen 9 don vi tu tu xuong mau thi duoc ps=3/5
cho ps a\b rut gon 3\5 neu them 6 vao mau giu nguyen tu ta duoc 1 ps moi rut gon =2\3 tim ps a\b
1,tim 1 ps bang ps 2/5 biet neu lay tu so cua ps do cong voi 45 va giu nguyen mau so thi duoc 1 ps moi bang ps 13/20
2,tinh dien tich toan phan cua hinh hop chu nhat co chieu dai 15cm,chieu rong 12cm,chieu cao 9,5cm.
3,bay gio la 2 gio.hoi sau it nhat bao nhieu lau nua thi kim gio va kim phut cua dong ho trung nhau.
4,vao nam tuoi chau bang 1/6 tuoi chau hien nay thi ong cua chau 60 tuoi,biet tong so tuoi cua 2 ong chau hien nay la 82 tuoi,tuoi chau hn la...
5,tim 1 stn biet neu xoa chu so hang don vi cua no di thi ta duoc so moi kem so phai tim la 1808 don vi.
1) Tim 1 so sao cho khi tu so cua PS 37/50 tru di so do va giu nguyen MS thi duoc ps moi la 1/2
2)Tim 1 SO SAO CHO khi tu so cua PS 13/16 + voi so do va giu nguyen MS thi duoc PS22 moi la 5/9
cho 2 phan so 5/8va 4/5 .tim ps a/b sao cho dem ps 5/8cong ps a/b va dem ps 4/5 tru a/b thi duoc 2 ps ma ps naygap 2 lan ps kia