Question

in what time will 1500 yeild 798.60 as compound interest a​

Answer 1

Answer:

It is given that

Principal (P)=1500

CI=496.50

So the amount (A)=P+SI

Substituting the values

=1500+496.50

=1996.50

Rate (r)=10% p.a.

We know that

A =P(1+r/100)

n

It can be written as

A/P = (1+r/100)

n

Substituting the values

1996.50/1500=(1+10/100)

n

By further calculation

199650/(1500×100)=(11/10)

n

So we get

1331/1000=(11/10)

n

(11/10)

3

=(11/10)

n

Here time n=3 years

(ii) It is given that

Principal (P)=12500

CI=3246.40

So the amount (A)=P+CI

Substituting the values

=12500+3264.40

= 15746.40

Rate (r)=8% p.a.

We know that

A =P(1+r/100)

n

It can be written as

A/P=(1+r/100)

n

Substituting the values

15746.40/12500=(1+8/100)

n

Multiply and divide by 100

1574640/(12500×100)=(27/25)

n

By further calculation

78732/(12500×5)=(27/25)

n

19683/(3125×5)=(27/25)

n

So we get

19683/15625 = (27/25)

(27/25)

3

=(27/25)

n

Here Period =3 years