數學應用題
2012-12-20 11:07 pm
志明要到飾物店購買一些藍色、紅色和橙色的氣球，可是當他到達店舖的時候，已經忘記要各買氣球多少個，只記得一共要買 100 個氣球；藍色氣球的數量是紅色氣球的三倍，而他帶的 745 元剛好足夠付款。如果藍色氣球、紅色氣球和橙色氣球的售價分別是 9 元、4 元和 7 元，問三種氣球應各買多少個？
回答 (3)
2012-12-25 12:12 am
✔ 最佳答案
見到你的題目是中文，所以我嘗試用中文回答。希望你會看得明白。看不明白可以來問我。圖片參考：http://imgcld.yimg.com/8/n/HA00132844/o/20121224161101.jpg
2012-12-21 4:58 am
B: Blue
R: Red
O: Orange
B + R + O = 100 [1]
B = 3R [2]
O = 100 - B - R = 100 - 3R - R = 100 - 4R [Putting 1 and 2, Get 3]
9B + 4R + 7O = 745 [4]
9*(3R) + 4R + 7*(100-4R) = 745
27R + 4R + 700 - 28R = 745
R=45/3 = 15 [[buy 15 red]]
So,
B = 3R = 3*15 = 45 [[buy 45 blue]]
O = 100 - 4R = 100 - 4*15 = 40 [[buy 40 orange]]
R: Red
O: Orange
B + R + O = 100 [1]
B = 3R [2]
O = 100 - B - R = 100 - 3R - R = 100 - 4R [Putting 1 and 2, Get 3]
9B + 4R + 7O = 745 [4]
9*(3R) + 4R + 7*(100-4R) = 745
27R + 4R + 700 - 28R = 745
R=45/3 = 15 [[buy 15 red]]
So,
B = 3R = 3*15 = 45 [[buy 45 blue]]
O = 100 - 4R = 100 - 4*15 = 40 [[buy 40 orange]]
2012-12-21 1:49 am
B: Blue
R: Red
O: Orange
B + R + O = 100 [1]
B = 3R [2]
O = 100 - B - R = 100 - 3R - R = 100 - 4R [Putting 1 and 2, Get 3]
9B + 4R + 7O = 745 [4]
9*(3R) + 4R + 7*(100-4R) = 745
27R + 4R + 700 - 28R = 745
R=45/3 = 15 [[buy 15 red]]
So,
B = 3R = 3*15 = 45 [[buy 45 blue]]
O = 100 - 4R = 100 - 4*15 = 40 [[buy 40 orange]]
2012-12-21 09:12:40 補充：
樓下朋友 kev******:
照抄都唔好這麼明目張膽.
請注意吃相.
Tony Chan 字
R: Red
O: Orange
B + R + O = 100 [1]
B = 3R [2]
O = 100 - B - R = 100 - 3R - R = 100 - 4R [Putting 1 and 2, Get 3]
9B + 4R + 7O = 745 [4]
9*(3R) + 4R + 7*(100-4R) = 745
27R + 4R + 700 - 28R = 745
R=45/3 = 15 [[buy 15 red]]
So,
B = 3R = 3*15 = 45 [[buy 45 blue]]
O = 100 - 4R = 100 - 4*15 = 40 [[buy 40 orange]]
2012-12-21 09:12:40 補充：
樓下朋友 kev******:
照抄都唔好這麼明目張膽.
請注意吃相.
Tony Chan 字
收錄日期: 2021-04-12 11:23:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121220000051KK00152