1)在一幅比例為1:2000的地圖中,某大樓的面積為310cm2 。求該大樓實際佔地多少m2?
2)某桌子的成本為$300。若該桌子以其標價的九折售出,則盈利百分率為20%,求該桌子的標價。
3)一隻碟子與一個杯子的重量之比為4:3。兩隻碟子和五個杯子的總重量為6.9kg。求一個杯子的重量。
三條數學題,求救!!
2012-07-26 6:43 pm
回答 (3)
2012-07-27 12:16 am
✔ 最佳答案
1) 先把 310 cm2 化成 m2 => 310 /100^2 = 0.031 m2地圖linear scale係 1:2000，而面積比例是 1:2000^2
佔地 = 0.031 x 2000^2 = 124,000 (m2)
2) 先計算盈利 = 300 x 20% = 60
設標價為 P
P x 0.9 - 300 = 60
P x 0.9 = 360
P = 360 / 0.9 = 400
3) 設杯子重量為C，碟子重量為P
P : C = 4 : 3 => P/C = 4/3 => P = 4/3 C
兩隻碟子和五個杯子的總重量為6.9kg
2P + 5C = 6.9
2 (4/3C) + 5C = 6.9
8 / 3 C + 5C = 6.9
8 C + 15C = 6.9*3
23C = 20.7
C = 0.9 (kg)
2012-07-26 8:14 pm
1.) (310*2000)/100^2
=620,000/10,000
=62m2
2.)(300*(1+0.2))/0.9
=(300*1.2)/0.9
=360/0.9
=$400
3.)(2(4/3)+5)/6.9
=(5+8/6)/6.9
=(38/6) / 6.9
=約0.92kg (取小數後2位)
=620,000/10,000
=62m2
2.)(300*(1+0.2))/0.9
=(300*1.2)/0.9
=360/0.9
=$400
3.)(2(4/3)+5)/6.9
=(5+8/6)/6.9
=(38/6) / 6.9
=約0.92kg (取小數後2位)
2012-07-26 7:14 pm
1) 310cm2 x 2000 = 620000cm2
化做米 = 620000cm2 / 100
= 6200m2
2) 假設桌子的標價為A
A x 0.9 - 300 = 300 x 0.2
A x 0.9 = 60 + 300
A x 0.9 = 360
A = 360 / 0.9
A = 400
3) 假設杯子的重量為C，碟子的重量為3/4C = 0.75C
2(0.75C) + 5C = 6.9
1.5C + 5C = 6.9
6.5C = 6.9
C = 6.9 / 6.5
C = 1.06kg
化做米 = 620000cm2 / 100
= 6200m2
2) 假設桌子的標價為A
A x 0.9 - 300 = 300 x 0.2
A x 0.9 = 60 + 300
A x 0.9 = 360
A = 360 / 0.9
A = 400
3) 假設杯子的重量為C，碟子的重量為3/4C = 0.75C
2(0.75C) + 5C = 6.9
1.5C + 5C = 6.9
6.5C = 6.9
C = 6.9 / 6.5
C = 1.06kg
收錄日期: 2021-04-13 18:51:30
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