F.2 Maths
2007-02-16 7:18 pm
In a purse , there are altogether 20 $5 and $0.5 coins with a total amount of $64.As compared , how many more $5 coins are there?
回答 (3)
2007-02-16 8:03 pm
There are $5 coins:
( 64 -4 ) / 5
= 60 / 5
= 12 (coins)
There are $0.5 coins:
( 64 - 12 X 5 ) / 0.5
=( 64 - 60 ) / 0.5
= 4 / 0.5
= 8 (coins)
There are coins :
12 + 8
= 20 (coins)
The answer should be ( 12 ) more $ 5 coins there.
( 64 -4 ) / 5
= 60 / 5
= 12 (coins)
There are $0.5 coins:
( 64 - 12 X 5 ) / 0.5
=( 64 - 60 ) / 0.5
= 4 / 0.5
= 8 (coins)
There are coins :
12 + 8
= 20 (coins)
The answer should be ( 12 ) more $ 5 coins there.
2007-02-16 7:33 pm
There are $5 coins:
( 64 -4 ) / 5
= 60 / 5
= 12 (coins)
There are $0.5 coins:
( 64 - 12 X 5 ) / 0.5
=( 64 - 60 ) / 0.5
= 4 / 0.5
= 8 (coins)
There are coins :
12 + 8
= 20 (coins)
The answer should be ( 12 ) more $ 5 coins there.
( 64 -4 ) / 5
= 60 / 5
= 12 (coins)
There are $0.5 coins:
( 64 - 12 X 5 ) / 0.5
=( 64 - 60 ) / 0.5
= 4 / 0.5
= 8 (coins)
There are coins :
12 + 8
= 20 (coins)
The answer should be ( 12 ) more $ 5 coins there.
參考: Me
2007-02-16 7:30 pm
Let x be the no.of $5coins, y be the no. of $0.5coins
x+y=20 -------------(1)
x=20-y
5x+0.5y=64--------(2)
5(20-y)+0.5y=64
100-5y+0.5y=64
-4.5y=-36
y=8
x=20-8
x=12
SO...12-8=4
there are 4 more $5coins!
x+y=20 -------------(1)
x=20-y
5x+0.5y=64--------(2)
5(20-y)+0.5y=64
100-5y+0.5y=64
-4.5y=-36
y=8
x=20-8
x=12
SO...12-8=4
there are 4 more $5coins!
參考: 自己計架!!xD
收錄日期: 2021-04-19 22:23:25
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