百分比 - 例題解析

答案 - B

解釋

32% = 32/100 = 8/25.

答案 - A

解釋

160% = 160/100 = 8/5	

答案 - A

解釋

0.8% = 0.8/100 = 0.008.

答案 - B

解釋

18% = 18/100 = 0.18

答案 - C

解釋

5% = 5/100 = 0.05

答案 - A

解釋

126% = 126/100 = 1.26	

答案 - D

解釋

0.06% = 0.06/100 = 0.0006.

答案 - D

解釋

3/4= (3/4*100)% = 75%

答案 - B

解釋

45% of 280+28% of 450 = (450/100*280)(28/100*450)
= (126+126) = 252

答案 - B

解釋

162/3% = 50/(3*100) = 1/6 = 0.166, 2/15 =0.133, 3rd number = 0.18, 3/7 = 0.42.
Clearly, 3/7 is largest.

答案 - A

解釋

Let the number be x. Then,
(4/5 x)-(65% of x)= 21 => 4x/5-65x/100=21 => 4x/5-13x/20=21
=> 16x-13x=420 =>3x=420 ?x=140.
Required number = 140.

答案 - A

解釋

Required % = (120/90*100)%= 400/3%

答案 - B

解釋

Required % = (5/1000*100)%= 1/2%=0.05%

答案 - A

解釋

Required % = (150/3500*100)%= 30/7%

答案 - A

解釋

B's salary is less than that of A by is less than that of a by {R/((100+R) )*100}%
= {20/((120) )*100}% = 50/3%

答案 - B

解釋

B's salary is more than that of A by {R/((100-R) )*100}%
= {25/((100-25) )*100}% = (25/75*100)=100/3%

答案 - A

解釋

Reduction % in consumption = {R/((100+R) )*100}%(20/120*100)%
= 50/3%

答案 - A

解釋

Increase % in consumption = {R/((100-R) )*100}% = {10/((100-10) )*100} = 100/9%

答案 - B

解釋

Let originally revenue obtained by Rs. x.
New revenue = (Consumption * Tax)
= (115% of 80% of Rs. x) = Rs(115/100*80/100*x)=Rs.92x/100
= 92% of the original.
Hence, the revenue is decreased by 8%.

答案 - A

解釋

Population after 2 years =  {176400 * (1+5/100)2 }
176400* 21/20*21/20=194481.