# Aptitude - Banker's Discount - Discussion

Discussion Forum : Banker's Discount - General Questions (Q.No. 12)
12.
The true discount on a bill of Rs. 540 is Rs. 90. The banker's discount is:
Rs. 60
Rs. 108
Rs. 110
Rs. 112
Explanation:

P.W. = Rs. (540 - 90) = Rs. 450. S.I. on Rs. 450 = Rs. 90.

 S.I. on Rs. 540 = Rs. 90 x 540 = Rs. 108. 450 B.D. = Rs. 108.

Discussion:
12 comments Page 1 of 2.

Anjum Bano said:   6 years ago
In a simple way,

By formula;

Sum(face value) = 540 & TD = 90.

We know that,
F = (BD*TD)/(BD-TD).
=> 540 = (BD * 90)/(BD-90),
=> 6BD - 540 = BD.
BD = 108 = Bankers discount.

Samanwita Nandi said:   6 years ago
Thank you all for the given explanation.

Sakthivel said:   7 years ago
A simple way:

P.W = Amount-TD.
P.W = 450.

B.G = (TD)^2/PW.
B.G = 8100/450 = 18.
B.G = 18.

B.G = BD-TD.
BD = B.G+TD.
BD = 18+90.
BD = 108.

SUKUMAR SATYEN said:   8 years ago
Following is explanation:

Given that,

Face Value of Bill (F) = Rs. 540.
True Discount (TD) = Rs. 90.

Banker's Discount (BD) is to be found out, which is simple interest on Face Value of Bill (F),

=> BD = F*R*T/100.

=> BD = 540*R*T/100....equation (1).

True Discount (TD) is simple interest on Present Worth (PW).

=> TD = PW*T*R/100.
=> 90 = PW*T*R/100.

=> 90/PW = T*R/100....equation (2).

We know, PW = F/[1+(T*R/100)].

=> PW*[1+(T*R/100)] = 540.
=> PW*[1+(90/PW)] = 540.

=> PW + 90 = 540.

=> PW = 540 - 90 = Rs. 450....equation (3).

From equation (2) & (3),

=> 90/450 = T*R/100....equation (4).

From equation (1) & (4),

=> BD = 540*90/450.
=> BD = Rs.108.

Thanks.

Priyanka said:   8 years ago
Given Data:

TD=90
Amount = 540
BD==?

We know that Amount = BD*TD/BD-TD
540 = BD*90/BD-90
540BD-48600 = 90BD

Have a nice day:).

@Anjana

T.D. means true discount.

@All

Look important formula at left side.

http://www.indiabix.com/aptitude/bankers-discount/formulas

What does T.D. mean ?