Find Simple interest using formula Tricky method

When take up some money from other for the personal or commercial purpose we pay some additional money to him after a certain period of time is called Interest. So we can also called this Interest as Simple Interest. So we can find the simple interest on Principal using some formula. This type of problem are given in Quantitative Aptitude which is a very essential paper in banking exam. Under below given some more example for your better practice.

• Find Simple interest using formula
  
  Formula : S.I = (P X R X T / 100)

Example 1 :
Find the Simple Interest on Rs. 75000 at 4% per annul for 4 years.
Answer:
we know Principal
P = Rs. 75000
R% = 4 per annul
T year = 4 years.
we just put the value into formula.
P = Rs. 75000, R = 4% p.a ( per annul ) T = 4 years.
S.I = ( P X R X T / 100 ) = 75000 X 4 X 4 /100 = 12000.
So the S.I is 12000.


Example 2:
On amount of 7530 at the rate of 18 p.c.p.a for 6 years What will be the simple interest ?
Answer :
S.I = P R T / 100
S.I = 7530 x 18 x 6 / 100
S.I = 8132.40
So the simple interest is 8132.40.


Example 3:
What will be the Ration of the Simple interest earned by certain amount at the same rate of interest for 5 years and 7 years ?
Answer :
step 1: Let Principal P and Rate of interest be R %.
So Required interest of 5 years is S.I = P R T / 100 = P x R x 5 / 100 = 5 PR / 100.
Required interest of 7 years is S.I = P R T / 100 = P x R x 7 / 100 = 7 PR / 100.
Step 2: Required ration is = 5 PR / 7 PR = 5 / 7 = 5 : 7.
So Required Ration is 5 : 7.


Example 4: Find the Simple Interest on Rs. 40000 at 25 / 4 % per annul for the period from 4th January, 2013 to 18th march, 2013.
Answer:
Step 1: First we calculate the period of time taken that is =
January = (31 – 4) = 27 days,
February = 28 days,
March = 18 day.
Add all together ( 27 + 28 + 18 ) = 73 / 365 year = 1 / 5 years.
Step 2: we know Principal P = 40000, and R = 25 / 4 % p.a.
Step 3: S.I = Rs. ( 40000 X 25 X 1 X 1 / 4 X 100 X 5 ) = Rs. 500
So the S.I is 500.


Example 5: What would be the simple interest earned by certain amount, at the same rate of interest for 4 years
and that for 8 years ?
Answer:
Let the principal be P
Rate of interest be R%
Time is 4 years and 8 years
So, Required ratio is = ( P x R x 4 /100 ) / ( P x R x 8 /100 ) = 4 / 8 = 1 / 2 = 1 : 2.


Example 6: What would be the simple interest on Rs. 85,000 at 15% per annum for 8 month
Answer: S.I = 85,000 x 2 x 15 / 3 x 100 = Rs. 8500.


Example 7: What would be the simple interest earned on an amount of Rs. 18,600 in 8 months at the rate of 18 / 2% per annul ?
Answer: 18,600 x 2 x 1 x 18 / 3 x 100 x 2 = 1116.


Example 8: What would be simple interest on Rs. 1860 from 2nd April to 21 June 2014 at the rate of 20 / 2% ?
Answer: 2nd April to 21 June 2014 = ( 28 + 31 + 21 ) = 80 days,
1860 x 20 x 1 x 20 / 2 x 100 x 3 = 1240.


Example 9: If Rs. 75 amounts to Rs. 90 in 2 years, What would be Rs. 120 amount to in 6 years at the same time rate percent p.a ?
Answer: P = 75, So SI = ( 90 – 75 ) = Rs. 15, and time = 2 years
So, rate = 100 x 15 / 75 = 20%.
P = Rs. 120, R = 20% time = 6 years,
So, SI = 120 x 20 x 6 / 100 = Rs. 144.