一條數學題, 不明白問什麼?

設Q的值為1,
P=1X(1-20%)
=0.8
Q比P多:1-0.8
=0.2
*考慮選擇D: (0.2/0.8)X100%
=+25%

驗算:0.8X(1+25%)
=0.8(125/100)
=1=P
所以,可得知Q比P大25%。
*(以0.8作分母是因為有"比P大"的字眼,因此要以P的值作為折扣基準,而非單計算兩者之百分差,如以下情況:

錯誤示範: 設Q的值為1,
P=1X(1-20%)
=0.8
所以,P與Q的百分差為:(1-0.8)X100
=+20%
所以選擇C。

設Q的值為1,
P=1X(1-20%)
=0.8
Q比P多:1-0.8
=0.2
*考慮選擇D: (0.2/0.8)X100%
=+25%

驗算:0.8X(1+25%)
=0.8(125/100)
=1=P
所以,可得知Q比P大25%。
*(以0.8作分母是因為有"比P大"的字眼,因此要以P的值作為折扣基準,而非單計算兩者之百分差,如以下情況:

錯誤示範: 設Q的值為1,
P=1X(1-20%)
=0.8
所以,P與Q的百分差為:(1-0.8)X100
=+20%
所以選擇C。

The answer is D, for sure! I'm amazed to see that so many answers presented above are wrong.
The critical thing is: the BASE.
P 比Q 少20% --> 20% is based on Q, i.e. P = Q x 80%.
A. P is 75% of Q --> 75% is based on Q, i.e. P = Q x 75%.
B. Q is 80% of P (Q 是80% 的P) -- 80% is based on P, i.e. Q = P x 80%.
C. Q is 20% greater than P -- 20% is based on P, i.e. Q = P x 120%.
D. Q is 25% greater than P -- 25% is based on P, i.e. Q = P x 125%.
(Your chinese translation of "P 是75% 的Q" should read "P 是Q的75%"! )
P = Q x 80% <=> Q = P x 125% , so the answer is D.

應該是 C 吧!

I guess the answer is D
if Q is 100 (ie5/5=1), then P is 80 (ie4/5=0.8)
P - 4/5 X 125% = 1 ieQ

I hope the answer is C.
From the Qs, P is 20% smaller than Q so it means P is the 80% of Q.
That&#39;s why answer A & B & D r not possible. If P is 20% smaller than Q then it means Q is 20% greater than P...Thus, the answer is C....If this Qs is about Logic problem...