Hari paid the first call amount late (at the time of second call payment). This means he is in arrears for the first call amount.
Calculation of Amount in Arrears:
Amount in arrears = 1200 shares × Rs 2 per share = Rs 2,400
Period of Delay:
The first call became due, but Hari paid it along with the second call which became due 1 month later.
Therefore, period of delay = 1 month
Interest Calculation:
Interest on Calls in Arrears = 100×12Amount in Arrears×Rate×Time (in months)
Using the standard rate of 10% per annum for calls in arrears:
Interest = 100×122400×10×1
Interest = 120024000 = Rs 20
The company will charge Rs 20 as interest from Hari for delaying the payment of first call by one month.