Question

hello plz solve the question given in the picture. 9 no.

Answer 1

step1 Find the interest when the principal = 2,000 , time = 3 yr

S.P1 = ( p × r × t ) / 100

S.P1 = 2000 × r × 3 / 100= ₹ 60r

step 2 Find the interest when principal
= ₹2400 , time = 3yr

S.P2 = (p × r × t ) / 100

S.P2 =( 2400 × r × 3) / 100 = ₹ 72r

according to the given statement :

S.P1 + 60 = S.P2

60r + 60 = 72 r

72r - 60r = 60

12r = 60 => r = 5 %

therefore,required rate of interest = 5%

Answer : rate = 5 %

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