Question

At what rate percent will a sum of rupees 640 be compounded to rupees 774.40 in two years ?

Answer 1

Given principal ( p ) = Rs 640

Time ( T ) = 2 years

Number of times Interest paid ( n ) = 2

Amount ( A) = Rs 774.40

Let the rate of interest= r

We know that,

p( 1 + r/100 )ⁿ = A

=> 640( 1 + r/100 )² =774.40

=> ( 1 + r/100)² = 774.40/640

=> ( 1 + r/100)² = ( 1.1 )²

=> 1 + r/100 = 1.1

=> r/100 = 1.1 - 1

=> r = 100 × 0.1

=> r = 10

Therefore ,

rate of interest ( r ) = 10%

••••

Answer 2

Step-by-step explanation:

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