# Aptitude - True Discount - Discussion

Discussion Forum : True Discount - General Questions (Q.No. 5)
5.
If Rs. 10 be allowed as true discount on a bill of Rs. 110 due at the end of a certain time, then the discount allowed on the same sum due at the end of double the time is:
Rs. 20
Rs. 21.81
Rs. 22
Rs. 18.33
Explanation:
S.I. on Rs. (110 - 10) for a certain time = Rs. 10.

S.I. on Rs. 100 for double the time = Rs. 20.

T.D. on Rs. 120 = Rs. (120 - 100) = Rs. 20.

 T.D. on Rs. 110 = Rs. 20 x 110 = Rs. 18.33 120

Discussion:
29 comments Page 1 of 3.

Teja said:   3 years ago
In the question itself( T.R =10), they doubled the time that means then P.W also changes.
So, calculate the P.W after change by (2 .T.R=20).

A = P.W(1+2.T.R/100).
110 = P.W(1+20/100).
P.W = 110(5/6).
T.D = A - P.W = 110 - 110(5/6) = 110/6 = 18.33.
(1)

Raman said:   4 years ago
We have to find the discount if the same sum i.e. 110 is supposed to be paid after 2 years instead of 1 year.

Gohil Rajnikant said:   5 years ago
Thanks @Abhisek.

Sudip Dhara said:   5 years ago
See, the true discount allowed is Rs. 10 and the amount to be paid after a certain time is Rs. 110.

We don't know the time and the present worth. So lets assume a value. Let's say the present worth is Rs.100, and the time is 1 year. Thus the Rate has to be 10%. Now double the time, so what is the present worth if Rs.110 was due in 2 years at 10%? It comes out to be Rs. 91.66. Thus the true discount becomes Rs.18.33.)
(2)

Jubair said:   6 years ago
Thanks @Abhishek.

Manisha said:   6 years ago
Thanks @Abhishek.

Swetha said:   6 years ago
Thank you @Abhishek.

Devendra said:   6 years ago
Thank you for explaining the answer.

Arvindkumargp said:   7 years ago
Thanks @Abhishek.

Keerthi said:   7 years ago
Given.

T.D = 10, AMOUNT = 110.
SO, BY USING THE FORMULA.
100*AMT/(100+RT)=100 * T.D/(RT),
WE KNOW THAT RT= 10,

Since the question asked to find out the T.D after double the time
RT=20,
So, by using the same above formula T.D=18.3333.
(1)