折扣 - 例題解析

答案 - B

解釋

P.W.= ((100 x Amount))/(100+(R x T))
= Rs {(100 x 9920)/(100 (3 x 8))}
= Rs  (100 x 9920)/124 
= Rs 8000

答案 - A

解釋

P.W. = ((100 x T.D.))/((R x T))
= Rs {(100 x 180)/(6 x 3/4)}
= Rs 4000

答案 - A

解釋

T.D = Rs 200 and S.I. = Rs 240 
Sum due = (S .I. x T.D.)/(S.I.-T.D.) 
= Rs ((240 x 200))/((240-200))
= Rs 1200

答案 - B

解釋

P.W. = (Amount)-(T.D.) 
= Rs (1860-60) 
= Rs 1800 
T.D. is S.I. on P.W. 
Rs. 60 is S.I. on Rs 1800 at 5% p.a. 
Time = ((100 x 60))/((5 x 1800)) years 
= 2/3 years 
= 2/3 x 12 months 
= 8 months

答案 - C

解釋

P.W.= ((100 x Amount))/(100+(R x T))
= Rs {(100 x 9920)/(100 (3 x 8))}
= Rs  (100 x 9920)/124 
= Rs 8000
T.D. = (Amount)-(P.W.)
= Rs (9920-8000)
= Rs 1920

答案 - A

解釋

P.W. = ((100 x T.D.))/((R x T))
= Rs {(100 x 180)/(6 x 3/4)}
= Rs 4000
Sum = (P.W.+T.D.) 
= Rs (4000+180) 
= Rs 4180 

答案 - D

解釋

T.D = Rs 200 and S.I. = Rs 240 
Sum due = (S .I. x T.D.)/(S.I.-T.D.) 
= Rs ((240 x 200))/((240-200))
= Rs 1200
T.D is S.I. on the sum. 
Rs. 240 is S.I. on Rs 1200 for a long time. 
R= ((100 x 240))/((1200 x 3))% p.a.
= 20/3% p.a

答案 - D

解釋

Amount = Rs 2575, T=4/12 years = 1/3 years, T.D = Rs. 75 
P.W. = (Amount) - (T.D.) = Rs (2575-75) = 2500. 
T.D. Is S.I. on P.W. 
R.s 75 is S.I. on Rs. 2500 or 1/3 years
Rate = ((100x75)/(2500x1/3))% p.a. = 9% p.a.

答案 - B

解釋

T.D. = Rs 26.25, T = 10/12  year=  5/6  year,R=6% p.a.
Let P.W. be Rs x. Then,
S.I. on Rs x at 6% p.a. for 5/6 year is Rs. 26.25
∴  (x * 6 * 5/6)/100 = 25.25 
=> x= (26.25 * 20) = 525
∴  (P.W.) + (T.D.) = Rs. (525+26.25) = Rs 551.25

答案 - B

解釋

S.I. = Rs. (x * 6 * 1/2)/100 
= Rs. 3x/100 and T.D. 
= Rs {(x * 78/12)/(100+(6 * 6/12) )}
= Rs. 3x/103
∴ 3x/100-3x/103 = 27 
=> (309x-300x) = (27 * 100 * 103)
=> x = ((27*100*103))/9 
= 30900