Question

A certain sum in certain time becomes rs560at the rate of 6%per anum at simple interst and the same sum amoun to rate of 2%in same duration find sum of time periods

Answer 1

Answer:

Let the amount be P Simple Interest Rate be i Interest amount per year = I P + 3 I = 1680/- P + 7 I = 1920/- By solving we get 4 I = 1920 ...

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Let the amount be P Simple Interest Rate be i Interest amount per year = I P + 3 I = 1680/- ... More

2 votes

4 years interest is 1920–1680=240 Per year is 60 3 years interest is 180 So initial amount ... More

1 vote

* Amount in 3-years= ₹ 1680 • Amount in 7- years= ₹1920 • Interest for ,4- years=₹ ... More

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Traditional method: Let the Principal amount be P and rate of interest be r. Amount in 3 ... More

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We have to calculate the rate of interest in this way. Interest earned in (7–3=4 ) 4 ... More

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Answer 2

The question is incomplete.

Question :

A certain sum in certain time becomes Rs.560 at the rate of 6%per anum at simple interest and the same sum amounts to Rs.320 at the rate of 2% in same duration. Find the sum and time period.

Answer :

The sum is Rs.200 and time is 6years.

Given :

Amount at 6% p.a = Rs.560

Amount at 2% p.a = Rs.320

To find :

The principal (P) and the time (T)

Solution :

Let P be Rs.P

and T be T years

We know ,

Amount = P + S.I

S.I = PRT/100

According to the first case ,

P + ( P×6×T) /100

According to the first case ,

P + ( P×2×T) /100

Difference in Amount :

560-320 = 240

Also, (P + ( P×6×T) /100) - (P + ( P×2×T) /100)

Hence,

(P + ( P×6×T) /100) - (P + ( P×2×T) /100) = 240

=> (P + 3 PT /50 ) - ( P + PT/50) 240

=>( 3PT/50) - ( PT/50) = 240

=>( 3PT - PT )/50 =240

=> 2PT /50 =240

=> 2PT =240×50

=> 2PT = 12000

=>PT = 12000/2

= 6000

S.I = PRT / 100

= (6000 × 6) / 100

= 36000/100

=360

Hence , Principal = Amount - S.I

= 560 - 360

= 200

S.I = PRT / 100

=> 360 = 6000T /100

6000T = 36000

T = 36000/6000

= 6 years

HENCE, the sum is Rs.200 and time is 6years.

# SPJ3