1)The Monthly salary of Mr Lee is $y. He spent 40% on rent, 35% on other
expenses and saves the rest.
a) Express the total amount Mr Lee saves in a year in terms of y.
b) If mr Lee plans to spend half of amount of salary a month on vocation, find the
percentage decrease in the total amount he saves in a year.
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1b題唔該最好有步驟!
thanks!!!
F.1 數學題
2012-08-16 2:56 am
回答 (2)
2012-08-16 6:08 am
1a) The total amount Mr Lee saves in a year in terms is:
$y (1 - 40% - 35%)
= $y (25%)
= $y / 4
1b) The total amount he saves in a year is :
=($y / 4) x 12
= $3y
∴ The percentage decrease in the total amount he saves in a year is :
=｛(y/2) / (3y)｝x 100%
= 16.67 %
2012-08-15 22:25:37 補充：
The percentage decrease in the total amount he saves in a year is :
=｛(y/2) / (3y)｝x 100%
=0.1667x100%
= 16.67 %
$y (1 - 40% - 35%)
= $y (25%)
= $y / 4
1b) The total amount he saves in a year is :
=($y / 4) x 12
= $3y
∴ The percentage decrease in the total amount he saves in a year is :
=｛(y/2) / (3y)｝x 100%
= 16.67 %
2012-08-15 22:25:37 補充：
The percentage decrease in the total amount he saves in a year is :
=｛(y/2) / (3y)｝x 100%
=0.1667x100%
= 16.67 %
2012-08-16 3:30 am
1a.
Ans = $y(1- 40%-35%) = $y(100%- 40%-35%) = $25%y = $y/4 = $0.25y
1b.
In a year, she should have saved: $y/4×12 = $3y.
She plans to spend half of amount of salary a month ($y/2) on vocation.
So she just saves 3y - y/2 = $5y/2.
The percentage decrease in the total amount he saves in a year
= (3y - 5y/2) / 3y × 100% = (y/2) / 3y × 100% = y/6 × 100% = (16+2/3)%
Ans = $y(1- 40%-35%) = $y(100%- 40%-35%) = $25%y = $y/4 = $0.25y
1b.
In a year, she should have saved: $y/4×12 = $3y.
She plans to spend half of amount of salary a month ($y/2) on vocation.
So she just saves 3y - y/2 = $5y/2.
The percentage decrease in the total amount he saves in a year
= (3y - 5y/2) / 3y × 100% = (y/2) / 3y × 100% = y/6 × 100% = (16+2/3)%
參考: me
收錄日期: 2021-04-13 18:55:23
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