17: Banker's discount

Example number 17.1, Page number 17.2

In [1]:
#importing modules
import math
from __future__ import division

#Variable declaration
P=2550;    #principal(Rs)
R=8;       #rate(%)
T=3/12;       #time(yrs)

#Calculation
TD=P*R*T/(100+(R*T));    #true discount(Rs)
BD=P*R*T/100;        #banker's discount(Rs)
BG=BD-TD;     #banker's gain(Re)

#Result
print "true discount is",TD,"Rs"
print "banker's discount is",BD,"Rs"
print "banker's gain is",BG,"Re"

true discount is 50.0 Rs
banker's discount is 51.0 Rs
banker's gain is 1.0 Re

Example number 17.2, Page number 17.2

In [2]:
#importing modules
import math
from __future__ import division

#Variable declaration
R=6;       #rate(%)
T=11/12;       #time(yrs)
BD=58.025;        #banker's discount(Rs)

#Calculation
P=BD*100/(R*T);    #principal(Rs)

#Result
print "principal is",P,"Rs"
print "answer given in the book is wrong"

principal is 1055.0 Rs
answer given in the book is wrong

Example number 17.3, Page number 17.2

In [3]:
#importing modules
import math
from __future__ import division

#Variable declaration
R=4;       #rate(%)
T=9/12;       #time(yrs)
TD=20;    #true discount(Rs)

#Calculation
BD=TD*(1+(R*T/100));        #banker's discount(Rs)

#Result
print "banker's discount is",BD,"Rs"

banker's discount is 20.6 Rs

Example number 17.4, Page number 17.3

In [4]:
#importing modules
import math
from __future__ import division

#Variable declaration
R=3;       #rate(%)
T=2;       #time(yrs)
TD=50;    #true discount(Rs)

#Calculation
BG=TD*R*T/100;     #banker's gain(Rs)

#Result
print "banker's gain is",BG,"Rs"

banker's gain is 3.0 Rs

Example number 17.5, Page number 17.3

In [5]:
#importing modules
import math
from __future__ import division

#Variable declaration
P1=1000;     #principal(Rs)
P2=1050;     #principal(Rs)
R=5;      #rate(%)

#Calculation
T=((P2*R*100/(P1*R))-100)/R;      #time(yrs)

#Result
print "time is",T,"yr"

time is 1.0 yr

Example number 17.6, Page number 17.3

In [6]:
#importing modules
import math
from __future__ import division

#Variable declaration
TD=90;    #true discount(Rs)
P=540;     #principal(Rs)

#Calculation
BD=((TD**2)/(P-TD))+TD;     #banker's discount(Rs)

#Result
print "banker's discount is",BD,"Rs"

banker's discount is 108.0 Rs

Example number 17.7, Page number 17.3

In [7]:
#importing modules
import math
from __future__ import division

#Variable declaration
R=5;       #rate(%)
T=2;       #time(yrs)
BG=15;     #banker's gain(Rs)

#Calculation
P=BG*100*(100+(R*T))/((R*T)**2);     #principal(Rs)

#Result
print "principal is",P,"Rs"

principal is 1650.0 Rs

Example number 17.8, Page number 17.3

In [8]:
#importing modules
import math
from __future__ import division

#Variable declaration
R=2;       #rate(%)
T=5;       #time(yrs)
BG=20;     #banker's gain(Rs)

#Calculation
PW=BG*(100**2)/((R*T)**2);     #present worth of bill(Rs)

#Result
print "present worth of bill is",PW,"Rs"

present worth of bill is 2000.0 Rs

Example number 17.9, Page number 17.3

In [9]:
#importing modules
import math
from __future__ import division

#Variable declaration
BG=25;     #banker's gain(Rs)
PW=10000;     #present worth of bill(Rs)

#Calculation
TD=math.sqrt(PW*BG);    #true discount(Rs)

#Result
print "true discount is",TD,"Rs"

true discount is 500.0 Rs

Example number 17.10, Page number 17.3

In [10]:
#importing modules
import math
from __future__ import division

#Variable declaration
BD=40;    #banker's discount(Rs) 
TD=30;    #true discount(Rs)

#Calculation
P=BD*TD/(BD-TD);      #sum(Rs)

#Result
print "sum is",P,"Rs"
print "answer given in the book is wrong"

sum is 120.0 Rs
answer given in the book is wrong

Example number 17.11, Page number 17.4

In [11]:
#importing modules
import math
from __future__ import division

#Variable declaration
BD=1;      #assume
BG=(7/57)*BD;    #banker's gain(Rs)
T=2;       #time(yrs)

#Calculation
R=BG*100/((BD-BG)*T);     #rate(%)

#Result
print "rate is",R,"%"

rate is 7.0 %

Example number 17.12, Page number 17.4

In [12]:
#importing modules
import math
from __future__ import division

#Variable declaration
BDbyTD=21/20;       #ratio of BD and TD
T=5/2;       #time(yrs)

#Calculation
R=(BDbyTD-1)*100/T;     #rate(%)

#Result
print "rate is",R,"%"

rate is 2.0 %