Solution:-

C₁ = (P × r × t)/$100$

$=(60,000\times 15\times 1)/100$

= ₹ $9,000$

P₁ = $60,000+9,000$

= ₹ $69,000$

C₂ = (P × r × t)/$100$

$=(69,000\times 15\times 1)/100$

= ₹ $10,350$

P₂ = $69,000+10,350$

= ₹ $79,350$

C₃ = (P × r × t)/$100$

$=(79,350\times 15\times 1)/100$

= ₹ $1190.25$

P₃ = $79,350+1,190.25$

= ₹ $91,252.5$

The compound interest paid by Nimisha,

C_total = C₁ + C₂ + C₃

= $9,000+10,350+1,190.25$

= ₹ $20,541$