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數學題 !! 唔該哂 !! (2)
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Two metals A and B are to be used for making two different alloys. The ratio by weight of A to B in the first alloy is 5 : 6 and that in the second alloy is 12 : 7. Now 44 kg of the first alloy and x kg of the second alloy are melted to produce another alloy so as the ratio of A to B in the new alloy is 17 :... 顯示更多 Two metals A and B are to be used for making two different alloys. The ratio by weight of A to B in the first alloy is 5 : 6 and that in the second alloy is 12 : 7. Now 44 kg of the first alloy and x kg of the second alloy are melted to produce another alloy so as the ratio of A to B in the new alloy is 17 : 13. The weights of A in first alloy is (5*44)/11 = 20 kg. The weights of B in first alloy is ____(1)____ kg. 還有 2 . 3 . 4 問題 !! " 數學題 !! 唔該哂 !! (3)個度 " Thank you !!
Two metals A and B are to be used for making two different alloys. The ratio by weight of A to B in the first alloy is 5 : 6 and that in the second alloy is 12 : 7. Now 44 kg of the first alloy and x kg of the second alloy are melted to produce another alloy so as the ratio of A to B in the new alloy is 17 : 13. Weight of metal A used in the first alloy is [5/(5+6)]*44 = 20 kg Weight of metal B used in the first alloy is [6/(5+6)]*44 = 24 kg Weight of metal A used in the second alloy is [12/(12+7)] * x = 12x/19 kg Weight of metal B used in the second alloy is [7/(12+7)] * x = 7x/19 kg Weight of metal A used = 20 + 12x/19 = (380 + 12x)/19 Weight of metal B used = 24 + 7x/19 = (456 + 7x)/19 Now the ratio of A:B is 17:13, so (380 + 12x)/19 : (456 + 7x)/19 = 17 : 13 (380 + 12x) : (456 + 7x) = 17 : 13 (380 + 12x) / (456 + 7x) = 17 / 13 13(380 + 12x) = 17(456 + 7x) 4940 + 156x = 7752 + 119x 37x = 2812 x = 76 So x = 76.
其他解答:
數學題 !! 唔該哂 !! (2)
發問:
Two metals A and B are to be used for making two different alloys. The ratio by weight of A to B in the first alloy is 5 : 6 and that in the second alloy is 12 : 7. Now 44 kg of the first alloy and x kg of the second alloy are melted to produce another alloy so as the ratio of A to B in the new alloy is 17 :... 顯示更多 Two metals A and B are to be used for making two different alloys. The ratio by weight of A to B in the first alloy is 5 : 6 and that in the second alloy is 12 : 7. Now 44 kg of the first alloy and x kg of the second alloy are melted to produce another alloy so as the ratio of A to B in the new alloy is 17 : 13. The weights of A in first alloy is (5*44)/11 = 20 kg. The weights of B in first alloy is ____(1)____ kg. 還有 2 . 3 . 4 問題 !! " 數學題 !! 唔該哂 !! (3)個度 " Thank you !!
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最佳解答:Two metals A and B are to be used for making two different alloys. The ratio by weight of A to B in the first alloy is 5 : 6 and that in the second alloy is 12 : 7. Now 44 kg of the first alloy and x kg of the second alloy are melted to produce another alloy so as the ratio of A to B in the new alloy is 17 : 13. Weight of metal A used in the first alloy is [5/(5+6)]*44 = 20 kg Weight of metal B used in the first alloy is [6/(5+6)]*44 = 24 kg Weight of metal A used in the second alloy is [12/(12+7)] * x = 12x/19 kg Weight of metal B used in the second alloy is [7/(12+7)] * x = 7x/19 kg Weight of metal A used = 20 + 12x/19 = (380 + 12x)/19 Weight of metal B used = 24 + 7x/19 = (456 + 7x)/19 Now the ratio of A:B is 17:13, so (380 + 12x)/19 : (456 + 7x)/19 = 17 : 13 (380 + 12x) : (456 + 7x) = 17 : 13 (380 + 12x) / (456 + 7x) = 17 / 13 13(380 + 12x) = 17(456 + 7x) 4940 + 156x = 7752 + 119x 37x = 2812 x = 76 So x = 76.
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