我要知點計.
1. a man increased the speed of his car by 12.5 %. By what percentage could be reduce his travelling time in the same journey ? 11%
2. the monthly income of a waiter was divided into 2 parts : basic salary , and the tips received , which were in the ration 3:2 . if the basic salary was increases by 25 %, but the tips received was decreased by 5 %, find its percentage change. +13 %
3. A is 30 % greater than B . How much is B less than A ? 23.08%
Thanks so much =)
F.3 Percentage 3Q ( in hurry )
2010-12-19 8:05 pm
回答 (3)
2010-12-19 8:52 pm
✔ 最佳答案
1)Let x % be the travelling time could be reduce :Speed x Time = Whole journey(1 + 12.5%) (1 - x%) = 11 - x% = 1 / 1.125x% = 1 - 1/1.125x% = 0.1111...x% = 11.1111...%x% = 11% (correct to neareast unit %)2)Basic salary + Tips = Income(3/5)Income + (2/5)Income = Income;Increased basic salary + Decreased Tips = New income(3/5)Income * (1 + 25%) + (2/5)Income * (1 - 5%) = New income0.75 Income + 0.38 Income = New income1.13 Income = New incomeAnswer is 13 % .
Please see the below :
Percentage change= (New income - Income) / Income x 100%= (1.13 income - Income) / Income x 100%= (1.13 - 1) / 1 x 100%= 0.13 x 100%= 13%
3) A is 30 % greater than B :(A - B) / B x 100% = 30%A - B = 0.3BA = 1.3BThe % of B less than A = (A - B) / A x 100%= (1.3B - B) / (1.3B) x 100%= (1.3 - 1) / 1.3 x 100%= 0.3 / 1.3 x 100%= 23.08%
2010-12-19 10:23 pm
THanks ! 你的表達比較容易明白!
2010-12-19 10:15 pm
B(1+30%)=A
A=1.3B
_________
1.3B-B/1.3B
23.08%2.d.p)
2010-12-19 14:50:48 補充：
其實呢課我都係學左冇耐,我把較難的地方簡化了.
A=1.3B
_________
1.3B-B/1.3B
23.08%2.d.p)
2010-12-19 14:50:48 補充：
其實呢課我都係學左冇耐,我把較難的地方簡化了.
收錄日期: 2021-04-21 22:18:47
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