Aptitude - Simple Interest - Discussion
Discussion Forum : Simple Interest - General Questions (Q.No. 13)
13.
A certain amount earns simple interest of Rs. 1750 after 7 years. Had the interest been 2% more, how much more interest would it have earned?
Answer: Option
Explanation:
We need to know the S.I., principal and time to find the rate.
Since the principal is not given, so data is inadequate.
Discussion:
97 comments Page 2 of 10.
Dilip said:
5 years ago
r is rate of interest.
Increased rate of interest is 1.02r because increased rate is 2%= (2÷100).
p*7*r=1750*100 ==> eq 1.
p*7*1.02*r=(1750+x)100==> eq 2 (x is incresed rs).
eq1& 2 is written as below.
7pr=175000 ==>eq 3.
7.14pr=175000+100x==> eq 4.
Upon solving both eqn 3*4.
0.14pr=100x==>eq 5.
by solving eqn 1 we get pr=25000.
By substituting that in eq 5.
0.14*250 = x.
so, x = 35.
Increased rate of interest is 1.02r because increased rate is 2%= (2÷100).
p*7*r=1750*100 ==> eq 1.
p*7*1.02*r=(1750+x)100==> eq 2 (x is incresed rs).
eq1& 2 is written as below.
7pr=175000 ==>eq 3.
7.14pr=175000+100x==> eq 4.
Upon solving both eqn 3*4.
0.14pr=100x==>eq 5.
by solving eqn 1 we get pr=25000.
By substituting that in eq 5.
0.14*250 = x.
so, x = 35.
Joby Jacob said:
9 years ago
Yes, I do agree with Amrendra Kumar. I think its option "B".
There is a total increase of 2 * 7% in the total interest of Rs. 1750.
i.e An additional 14% will be the extra amount added view increase in 2% from the existing SI.
If, we consider the existing total SI as 100%, ie Rs. 1750 as 100%, then the increment is 114% of 1750.
=1750 * 114/100 = 1995.00.
Net increase is 1995 - 1750 = 245.
There is a total increase of 2 * 7% in the total interest of Rs. 1750.
i.e An additional 14% will be the extra amount added view increase in 2% from the existing SI.
If, we consider the existing total SI as 100%, ie Rs. 1750 as 100%, then the increment is 114% of 1750.
=1750 * 114/100 = 1995.00.
Net increase is 1995 - 1750 = 245.
Pappu das said:
8 years ago
Correct answer - c - 350, how.
In 7 yr SI - RS. 1750
In 1 yr SI - RS . 250, so interest increase by R - 10%.
Get principal through formula - P*R*T/100,
1750 = P * 10 * 7 /100.
P = 2500.
So, increase rate of interest by 2% , ( 10%+2%) = 12 %.
SI at 12 % interest rate on 7 years on same principal = 2100,
Finally - SI at 12% - SI at 10 %.
2100 - 1750 = 350 answer.
In 7 yr SI - RS. 1750
In 1 yr SI - RS . 250, so interest increase by R - 10%.
Get principal through formula - P*R*T/100,
1750 = P * 10 * 7 /100.
P = 2500.
So, increase rate of interest by 2% , ( 10%+2%) = 12 %.
SI at 12 % interest rate on 7 years on same principal = 2100,
Finally - SI at 12% - SI at 10 %.
2100 - 1750 = 350 answer.
Promish said:
1 decade ago
Hey friends I think the answer will be option A i.e. 35,
Explanation:
let r be 100,and it is increased by 2% for second case, so for the second case r will be 102.
I = Rs. 1750, t=7 yrs, r=100(let).
So P = (I*100)/r*t=(1750*100)/(100*7) = 250.
So use this P for the second case,and S.I will be,
I = (P*t*r)/100=(250*7*102)/100 = 1785.
So the increase will be = Rs.(1785-1750) = Rs.35.
Explanation:
let r be 100,and it is increased by 2% for second case, so for the second case r will be 102.
I = Rs. 1750, t=7 yrs, r=100(let).
So P = (I*100)/r*t=(1750*100)/(100*7) = 250.
So use this P for the second case,and S.I will be,
I = (P*t*r)/100=(250*7*102)/100 = 1785.
So the increase will be = Rs.(1785-1750) = Rs.35.
Aakash said:
7 years ago
The answer should be 35.
Given:
p*r*7/100 = 1750.
According to question;
new rate = r+2%of r.
new rate = r+0.02*r.
new rate = 1.02*r.
Hence new SI = p*1.02*r*7/100,
new Si = 1.02*p*r*7/100,
new Si = 1.02*1750,
= 1785.
Difference = 1785-1750 = 35.
Given:
p*r*7/100 = 1750.
According to question;
new rate = r+2%of r.
new rate = r+0.02*r.
new rate = 1.02*r.
Hence new SI = p*1.02*r*7/100,
new Si = 1.02*p*r*7/100,
new Si = 1.02*1750,
= 1785.
Difference = 1785-1750 = 35.
Moncy Kurien said:
2 decades ago
This answer would actually keep changing according to the rate of interest that we take which will in-turn change the principal amount. That is if we take r as 5 and 7 then the answer will be Rs 700. So unless and until we are provided with the correct principal amount I guess we cannot find the exact answer.
Please correct me if I am wrong. Thank you.
Please correct me if I am wrong. Thank you.
Rahul said:
1 decade ago
Let the rate of S.I is 100 (initially).
In the first case:
Sum = (S.I x 100)/(Rate of interest x time).
So sum = (1750 x 100)/(100 x 7) = 250.
In the 2nd case:
The interest rate is 2% more, so the interest rate is 102%.
S.I = (sum x time x Rate of interest)/100.
= (250 x 7 x 102)/100 = 1785.
So the gain in S.I is (1785-1750) = 35.
Thank You.
In the first case:
Sum = (S.I x 100)/(Rate of interest x time).
So sum = (1750 x 100)/(100 x 7) = 250.
In the 2nd case:
The interest rate is 2% more, so the interest rate is 102%.
S.I = (sum x time x Rate of interest)/100.
= (250 x 7 x 102)/100 = 1785.
So the gain in S.I is (1785-1750) = 35.
Thank You.
Tanmayi Melavanki said:
4 years ago
I think the answer should be 35. I am not getting why they are saying data inadequate.
Old interest=(P*R*7)/100= 1750.
New interest= [P*R*7*(102/100)]/100.
=[(P*R*7)/100]*[102*100].
=1750*(102/100),
=1785.
So, the answer is = New Interest- Old interest = 1785 - 1750 = 35.
Old interest=(P*R*7)/100= 1750.
New interest= [P*R*7*(102/100)]/100.
=[(P*R*7)/100]*[102*100].
=1750*(102/100),
=1785.
So, the answer is = New Interest- Old interest = 1785 - 1750 = 35.
(1)
Prethi said:
1 decade ago
Please anyone correct me if I'm wrong. I solved the problem in following way
let p be the sum and r rate of interest
1750=p*r*7/100..........(1)
Now r if increased by 2% interest becomes 1.2r
Now equation for S.I=p*1.2r*7/100
By multiplying equation 1 by 1.2 on both sides we get
p*1.2r*7/100=1.2*1750=2100
So 2100-1750=350 is the answer
let p be the sum and r rate of interest
1750=p*r*7/100..........(1)
Now r if increased by 2% interest becomes 1.2r
Now equation for S.I=p*1.2r*7/100
By multiplying equation 1 by 1.2 on both sides we get
p*1.2r*7/100=1.2*1750=2100
So 2100-1750=350 is the answer
Koko said:
7 years ago
Here, the 2% more interest means in absolute S.I terms, as in if it was 6% interest then how much more would you earn if you had 8% interest, not 6% x 1.02 which is 6.12%. Since we cannot calculate the S.I itself, we will never be able to find the answer. Please anyone help me to get it.
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