A sum of Rs.3000 becomes Rs.6000 when invested in a scheme of simple interest. If the annual rate of interest and the number of years for which the sum was invested are same, then what is the annual rate of interest?

10 percent

Principal( P) =  3000 Rs

Rate (R%)   =  R

Time ( T )    =   R

Amount  =  6000 Rs

Interest =  Amount - Principal   = 6000 - 3000 =  Rs 3000

A.T.Q.

  Rate and Time are equal= R

Interest = \(\frac{Principal ×Rate × Time }{100}\)

3000     =   \(\frac{3000 × R × R }{100}\)

   1       =    \(\frac{R2 }{100}\)

  ⇒ 100=   R²

  ⇒ R = 10% p.a