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Hi there! Have questions about your homework? At Brainly, there are 60 million students who want to help each other learn. Questions are usually answered in less than 10 minutes. Try it for yourself by posting a question! :D

a)In how much time will simple interest on a sum of money be 2/5th of the sum, at the rateof 10% per annum b) At what rate of

interest will simple interest be half the principal in 5 years. c)A sum of money amounts to Rs. 1265 in 3 years and to Rs.1430 in 6 years, at simpleinterest. Find the sum and the rate percent.

P = Principal amount R = Rate percent T = Time a).⇒A/Q, S.I of sum = 2/5 of sum

therefore time = 4 years

b).⇒A/Q, S.I = 1/2 of principal amount in five years

therefore Rate = 10%per annum

c).⇒Sum of money (A) = (P+S) ,where P = principal amount and S is S.I of three years A/Q, Sum of money in 3 years() = 1265 or P+S = 1265 -------(1) Sum of money in 6 years () = (P+2S) or, P+2S = 1430 --------(2) Now ,Equation (2)-(1) ,, S = 165 = S.I of three years then P = 1100 = principal amount now,

A) let the sum of be x 2x/5=x*10*t/100 ⇒2=10t/20 ⇒t=4 yrs

b)let the principal be x si=x/2 x/2=x*5*r/100 ⇒50=5r ⇒r=10%

c) amt after 3 yrs=P+I=1265..........(i) amt after 6 yrs=P+2I=1430............(ii) subtracting (ii) frm (i) we get I=165 substituting in eqn (i) we get,P+165=1165 ⇒P=1100 165=1100*r*3/100 ⇒r=5%