Question

In how many years will a sum of money double itself at 10 % p.a. interest

Answer 1

Let,principal=x
Amount=2x
Rate=8percent
now,
p=A*100/100+TR
or,x=2x*100/100+T*12
or,100+12T=200
or,T=200- 100/12=8.333 years

Answer 2

$\huge\boxed{\texttt{\fcolorbox{Red}{aqua}{Hey Mate!!!}}}$

$<b><i><font face=Copper black size=4 color=blue>$
Here is your answer
Let P = x
A = 2x
SI = x
R = 10%
Let T = t years

As we know the formula
SI =PRT/100
$x = \frac{x \times 10 \times t}{100} \\ t = \frac{x \times 100}{x \times 10} \\ t = 10 \: years$
Therefore
Time is 10 years

$\large{\red{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\boxed{\underline{\underline{\underline{Hope\:it\: helps\: you}}}}}}}}}}}}}}}$