... ca hc sinh lp 5A, hc sinh lp 5B, hc sinh lp 5C, 10 hc sinh lp 5D cn bit gỡ? (nng sut chung ca s hc sinh ny.) ? Mun tỡm nng sut ca hc sinh lp 5A, hc sinh lp 5B, hc sinh lp 5C, hc 10 sinh lp 5D cn ... 120 hc sinh lp 5A, hc sinh lp 5B, hc sinh lp 5C, hc sinh lp 5D 10 1 1 + + + = lm c l: (sõn trng) 40 30 60 120 12 Thi gian hc sinh lp 5A, hc sinh lp 5B, hc sinh lp 5C, 10 hc sinh lp 5D hon thnh ... lp 5C lm cl: ì = (phn) 3 s HS lp 5D lm c l: 10 ì = (phn) 10 10 3 hc sinh lp 5A, hc sinh lp 5B, hc sinh lp 5C, hc sinh lp 5D 10 lm c l: + 12 + + = 30 (phn) Thi gian hc sinh lp 5A, hc sinh lp 5B,...