Question

In how much time will a certain sum be $1.5$ times the principal at $10\%$ per annum?

• A. $1$ year
  
• B. $2$ year
  
• C. $4$ year
• D. $5$ year
  

Answer 1

The correct option is D $5$ year

Let the Principal be $x$

and the Time taken be $t$

and rate of increase per annum $=10$%

Now, According to given Conditions

$1.5x=x+t\times \left(\frac{10}{100}x\right)\Rightarrow 0.5x=t\times \left(0.1\right)x\Rightarrow t=5years$