At what percent per annum will ₹6000 amounts to ₹7986 in 3 years if the interest is compounded annually?

10%

From the formula for Amount with compound interest . we know,

A = P(1+$\frac{R}{100})^t$

7986 = 6000 [ 1 + \(\frac{R}{100}\) ]³

\(\frac{1331}{1000}\) =  [ 1 + \(\frac{R}{100}\) ]³

( \(\frac{11}{10}\) )³ =  [ 1 + \(\frac{R}{100}\) ]³

 \(\frac{11}{10}\)  = 1 + \(\frac{R}{100}\)

\(\frac{R}{100}\)  = \(\frac{1}{10}\) 

R = 10%

So, Rate of interest is 10%.