Đại lượng tỉ lệ thuận - Bài tâp trung bình

Home Toán lớp 7 - Sách KNTT Bài 22: Đại lượng tỉ lệ thuậnBài tập trung bình

{"common":{"save":0,"post_id":"5795","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"8305","post_id":"5795","mon_id":"1158532","chapter_id":"1158659","question":"Gi\u1ea3 s\u1eed s\u1ed1 gi\u1edd làm vi\u1ec7c t và ti\u1ec1n công t\u01b0\u01a1ng \u1ee9ng M (tri\u1ec7u \u0111\u1ed3ng) c\u1ee7a m\u1ed9t k\u0129 s\u01b0 t\u1ef1 do là hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi nhau theo công th\u1ee9c M = k.t .<\/p>Tìm h\u1ec7 s\u1ed1 t\u1ec9 l\u1ec7 k bi\u1ebft \u1ee9ng v\u1edbi 12 gi\u1edd làm vi\u1ec7c thì ti\u1ec1n công c\u1ee7a k\u0129 s\u01b0 là 6 tri\u1ec7u \u0111\u1ed3ng.<\/p>","options":["A. <\/strong>k = 6","B. <\/strong>k = 2","C. <\/strong>k = 12","D. <\/strong>k = 0,5"],"correct":"4","level":"2","hint":"T\u1eeb công th\u1ee9c y = k.x suy ra k = $\\dfrac{y}{x}$<\/span><\/p>","answer":"Vì M = k.t, theo \u0111\u1ec1 bài ta có:  6 = k . 12 suy ra k = 6<\/span>12<\/span><\/span>  = 0,5<\/p>V\u1eady k = 0,5<\/p>\u0110áp án \u0111úng là  D. <\/strong>k = 0,5<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-05-28 10:36:11","option_type":"txt","len":0},{"id":"8307","post_id":"5795","mon_id":"1158532","chapter_id":"1158659","question":"Gi\u1ea3 s\u1eed s\u1ed1 gi\u1edd làm vi\u1ec7c t và ti\u1ec1n công t\u01b0\u01a1ng \u1ee9ng M (tri\u1ec7u \u0111\u1ed3ng) c\u1ee7a m\u1ed9t k\u0129 s\u01b0 t\u1ef1 do là hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi nhau theo công th\u1ee9c M = k.t .<\/p>Bi\u1ebft \u1ee9ng v\u1edbi 12 gi\u1edd làm vi\u1ec7c thì ti\u1ec1n công c\u1ee7a k\u0129 s\u01b0 là 6 tri\u1ec7u \u0111\u1ed3ng, tính s\u1ed1 ti\u1ec1n công mà k\u0129 s\u01b0 nh\u1eadn \u0111\u01b0\u1ee3c khi làm vi\u1ec7c trong 25 gi\u1edd.<\/p>","options":["A.<\/strong> 12 tri\u1ec7u \u0111\u1ed3ng","B. <\/strong>12,5 tri\u1ec7u \u0111\u1ed3ng","C.<\/strong> 25 tri\u1ec7u \u0111\u1ed3ng","D.<\/strong> 30,5 tri\u1ec7u \u0111\u1ed3ng"],"correct":"2","level":"2","hint":"","answer":"Vì M = k.t, theo \u0111\u1ec1 bài ta có:  6 = k . 12 suy ra k = 6<\/span>12<\/span><\/span>  = 0,5<\/p>Do \u0111ó M = 0,5 . t<\/p>Khi t = 25 gi\u1edd thì M = 0,5 . 25 = 12,5 tri\u1ec7u \u0111\u1ed3ng<\/p>\u0110áp án \u0111úng là  B. <\/strong>12,5 tri\u1ec7u \u0111\u1ed3ng<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-05-28 10:41:09","option_type":"txt","len":2},{"id":"8342","post_id":"5795","mon_id":"1158532","chapter_id":"1158659","question":"Gi\u1ea3 s\u1eed s\u1ed1 gi\u1edd làm vi\u1ec7c t và ti\u1ec1n công t\u01b0\u01a1ng \u1ee9ng M (tri\u1ec7u \u0111\u1ed3ng) c\u1ee7a m\u1ed9t k\u0129 s\u01b0 t\u1ef1 do là hai \u0111\u1ea1i l\u01b0\u1ee3ng t\u1ec9 l\u1ec7 thu\u1eadn v\u1edbi nhau theo công th\u1ee9c M = k.t .<\/p>Bi\u1ebft \u1ee9ng v\u1edbi 12 gi\u1edd làm vi\u1ec7c thì ti\u1ec1n công c\u1ee7a k\u0129 s\u01b0 là 6 tri\u1ec7u \u0111\u1ed3ng, tính s\u1ed1 gi\u1edd mà k\u0129 s\u01b0 làm vi\u1ec7c \u0111\u1ec3 nh\u1eadn \u0111\u01b0\u1ee3c ti\u1ec1n công là 10,5 tri\u1ec7u \u0111\u1ed3ng.<\/p>","options":["A.<\/strong> 21 gi\u1edd","B.<\/strong> 19 gi\u1edd","C.<\/strong> 5,25 gi\u1edd","D. <\/strong>5 gi\u1edd"],"correct":"1","level":"2","hint":"","answer":"Vì M = k.t, theo \u0111\u1ec1 bài ta có:  6 = k . 12 suy ra k = 6<\/span>12<\/span><\/span>  = 0,5<\/p>Do \u0111ó M = 0,5 . t<\/p>Khi M = 10,5 tri\u1ec7u \u0111\u1ed3ng thì  10,5 = 0,5 . t ⇒ t =  10,5<\/span>0,5<\/span><\/span>   = 21 gi\u1edd .<\/p>\u0110áp án \u0111úng là   A.<\/strong> 21 gi\u1edd<\/span><\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"1","date":"2022-05-29 02:24:57","option_type":"txt","len":1}]}