Question

in what time will 100 become 200 at 10% rate of interest per annum​

Answer 1

Formula of Simple Interest

=P*R*T/100

P=100

R=10%

T=x(say)

Amount=200

200=100×10×x/100

x=200/10

x=20

Answer 2

To find:

$\to$The time

Information given in the question:

• Principle=100
• Amount=200
• Rate of interest per annum=10%

Solution:

Let,The time be $x$ years

$\to$Using formula:

Simple interest=(Amount - Principle)

So,Simple interest=(200 - 100)

                              =100

$\to$Using formula:

$\to$Simple Interest=$\frac{Principle*Time*Rate of interest per annum}{100}$

Putting time as $x$ in the place of time in the formula of simple interest and solving,

Now,Solving the formed equation,

$100=\frac{100*x*10}{100}$

$\to or,10x=100$

$\to or, x=\frac{100}{10}$

$\to or,x=10$

So,The time=10 years

Verification:

Putting time as 10 in the equation,

$100=\frac{100*10*10}{100}$

$\to or,100=\frac{10000}{100}$

$\to or,100=100$

Therefore,L.H.S=R.H.S

Hence,Verified

Additional Information:

$\to$Amount=(Principle + Simple interest)

Answer:

The time=10 years