In a supermarket, the price of an apple is $2.5, and an orange is $3. Alan got $2 left after buying some apples. However, he would need $2 more if he wanted to buy the same number of oranges. Find the number of apples he bought.
( 必須有 算式 , 步驟 , 答案 , 如沒, 沒可能有分給 )
唔識計.......
2007-01-01 8:26 pm
回答 (3)
2007-01-01 8:52 pm
✔ 最佳答案
Let the number of apple is XAlan got 2.5X+2 dollars in his pocket before
If he would like to buy orange in the same Pcs. He need 2 more dollors
i.e. 2.5X+2+2 which is equal to 3X
2.5X+4 = 3X
4 = 0.5X
X = 8
So Alan bought 8 apples
Proof:
8apples cost 8x2.5=$20
8oranges cost 8x3=$24
Alan got $20+$2 = 22dollors
2more money means 22+2 = $24
Thanks
參考: Myself
2007-01-01 8:52 pm
Let x be the money Alan had, and y be the number of apples he bought,
x-2 = 2.5y ..... (a)
x+2 = 3y ..... (b)
(b) - (a), we have
(x-2) - (x+2) = 3y-2.5y
-2-2 = -0.5y
0.5y = 4, y=8
Therefore, the number of apples Alan bought was 8.
x-2 = 2.5y ..... (a)
x+2 = 3y ..... (b)
(b) - (a), we have
(x-2) - (x+2) = 3y-2.5y
-2-2 = -0.5y
0.5y = 4, y=8
Therefore, the number of apples Alan bought was 8.
參考: myself
2007-01-01 8:32 pm
Let Alan has $x originally.
So from the given, he has bought (x-2)/2.5 apples.
So the same number of oranges, i.e. (x-2)/2.5, will cost $(x+2) from the given which is equivalent to 3[(x-2)/2.5] since an orange costs $3.
Therefore,
3(x-2)/2.5 = x+2
3x - 6 = 2.5x + 5
0.5x = 11
x = 22
And number of apples Alan bought = (22-2)/2.5 = 8
Therefore Alan originally has $22 and he did buy 8 apples.
So from the given, he has bought (x-2)/2.5 apples.
So the same number of oranges, i.e. (x-2)/2.5, will cost $(x+2) from the given which is equivalent to 3[(x-2)/2.5] since an orange costs $3.
Therefore,
3(x-2)/2.5 = x+2
3x - 6 = 2.5x + 5
0.5x = 11
x = 22
And number of apples Alan bought = (22-2)/2.5 = 8
Therefore Alan originally has $22 and he did buy 8 apples.
參考: My Maths knowledge
收錄日期: 2021-05-03 05:57:11
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