Question

A sum of money amounts to rupees 1265 in 3 years and to Rupees 1430 in 6 years at simple interest find the sum and rate percent.

Answer 1

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solve For 3 years :
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given, Amount (A ) = Rs 1265

Time (T ) = 3 yr ,

since , we know ,

Amount = P + S.I

then ,

S.I = A - P

S.I = 1265 - P

P × R × 3 / 100 = 1265 - P

PR = 100 ( 1265 - P ) / 3

PR = 126500 - 100P / 3. _______ eq.(1)

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solve for 6 years :
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given , amount = Rs 1430 , T = 6 yr

S.I = A - P

S.I = 1430 - P

P × R × T / 100 = 1430 - P

P × R × 6 = 100 ( 1430 - P )

PR = ( 143000 - 100P ) / 6 ______eq.(2)

equalize eq. (1 ) and (2 ) , we get

PR = PR

(126500 - 100P) / 3 =( 143000 - 100P )/ 6

2 (126500 - 100P ) = ( 143000 - 100p )

253000 - 200P = 143000 - 100P

253000 - 143000 = - 100P + 200P

110000 = 100 P

P = Rs 1100 ( required sum )

put value of ' P ' in eq. ( 1 ) , we get

1100 × R = (126500 - 100 × 1100 ) / 3

1100 R = 16500 / 3

R = 16500 / 3 × 1100

R = 16500 / 3300

R = 165 / 33

R = 5 % ( required rate )

therefore,

sum = Rs 1100 , and Rate = 5 %

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Your Answer : sum = Rs 1100 , R = 5 %
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Answer 2

Answer:

Step-by-step explanation:

Hope it helps u