A sum of ₹6000 is invested at 20% per annum. If interest is compounded half-yearly, the amount received after 18 months will be:

1. Half-yearly rate = 20%/2 = 10%; number of half-years in 18 months = 3. 2. Amount = 6000 × (1 + 10/100)³ = 6000 × (1.1)³. 3. = 6000 × 1.331 = ₹7,986. _Source: RRB Group D CEN-02/2018 PYQ, Q.24._