# Aptitude - Banker's Discount - Discussion

Discussion Forum : Banker's Discount - General Questions (Q.No. 11)

11.

The present worth of a sum due sometime hence is Rs. 576 and the banker's gain is Rs. 16. The true discount is:

Answer: Option

Explanation:

T.D. = P.W. x B.G. = 576 x 16 = 96.

Discussion:

9 comments Page 1 of 1.
SUKUMAR SATYEN said:
8 years ago

Following is explanation:

Banker's Discount (BD) is simple interest on Face Value of Bill (F),

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

We know, Banker's Gain (BG) is difference between Banker's Discount (BD) and True Discount (TD).

=> BG = BD - TD.

=> 16 = BD - TD....equation (1).

Given that,

Present Worth (PW) = Rs. 576.

True Discount (TD) is to be found out, which is simple interest on Present Worth (PW).

We know that,

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

=> TD = 576*T*R/100....equation (2).

From equation (1) & (2),

=> 16 = (F*R*T/100) - (576*T*R/100).

=> 16 = (F-576)*(R*T/100)....equation (3).

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

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

=> 576*[1+(T*R/100)] = F.

=> [1+(T*R/100)] = F/576.

=> (T*R/100) = (F/576)-1.

=> (T*R/100) = (F-576)/576....equation (4).

From equation (3) & (4),

=> 16 = (F-576)*(F-576)/576.

=> 16*576 = (F-576)*(F-576).

=> square root of (16*576) = (F-576).

=> 576±96 = F.

=> F = 672 or 480.

We take, F = 672.

From equation (2) & (4),

=> TD = 576*{(F-576)/576}.

=> TD = 672-576 = Rs. 96.

Here, F = 480 is not taken otherwise, TD would be negative.

Thanks.

Banker's Discount (BD) is simple interest on Face Value of Bill (F),

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

We know, Banker's Gain (BG) is difference between Banker's Discount (BD) and True Discount (TD).

=> BG = BD - TD.

=> 16 = BD - TD....equation (1).

Given that,

Present Worth (PW) = Rs. 576.

True Discount (TD) is to be found out, which is simple interest on Present Worth (PW).

We know that,

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

=> TD = 576*T*R/100....equation (2).

From equation (1) & (2),

=> 16 = (F*R*T/100) - (576*T*R/100).

=> 16 = (F-576)*(R*T/100)....equation (3).

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

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

=> 576*[1+(T*R/100)] = F.

=> [1+(T*R/100)] = F/576.

=> (T*R/100) = (F/576)-1.

=> (T*R/100) = (F-576)/576....equation (4).

From equation (3) & (4),

=> 16 = (F-576)*(F-576)/576.

=> 16*576 = (F-576)*(F-576).

=> square root of (16*576) = (F-576).

=> 576±96 = F.

=> F = 672 or 480.

We take, F = 672.

From equation (2) & (4),

=> TD = 576*{(F-576)/576}.

=> TD = 672-576 = Rs. 96.

Here, F = 480 is not taken otherwise, TD would be negative.

Thanks.

Anshika said:
8 years ago

How these all formulas on bankers discount and true discount are obtained? ate they baseless. Is there any existence of these type of formula in mathematics?

Suman Roy said:
9 years ago

How formula is obtained ?

Yeksh said:
10 years ago

What does present worth mean?

KING said:
1 decade ago

This formula is obtained by the banker gain formula i.e B.G=[T.D]*[T.D]/P.W

Maria said:
1 decade ago

T.D is True Discount

Pramod said:
1 decade ago

P.W is Present Worth. B.G is Bankers Gain.

Kanika said:
1 decade ago

can any body explain how is d formula obtained?

Ankita said:
1 decade ago

What is T.D , P.W , B.G?

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