The compund interest on a certain sum for 2 years is RS 41 and simple interest is RS 40. Then the rate per annum is ?
Answers
Step-by-step explanation:
The simple and compounded interest on a certain sum for two years are respectively 40 and 41 find the rate and sum?
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Well there is a very easy way to solve this question but let me first explain the conventional method
Here we can see that in both the cases of SI and CI the principal and rate of interest is same
SI = P*R*2/100 ……(1)
CI = A - P
CI = P*(1+R/100)^2 - P
CI = P*[(1+R/100)^2 - 1]
CI = P*[(10000 + R^2 + 200R -10000)/10000]
CI = P*[(R^2 + 200R)/10000] ……….(2)
Dividing eq.(1) by eq.(2)
40/41 = (2PR /100)/ [P*(R^2 + 200R)/10000]
By solving this R = 5%
By putting this value in equation.(1)
Sum = 400
Or
Without copy pen :-
Simple interest is Rs.40 in 2 years
In one year it will be Rs.20
In first year SI and CI will be same or RS.20 but in second year CI is Rs.1 more than the SI
Rate of interest R = (1/20)*100 or 5%
Simple interest of Rs.40 is a 10% value of sum
Sum = (40*100)/10 or 400 Rs.
Answer:
sum is equal to 400
I think this help you