What is the minimum number of 20-amp 277-volt branch circuits required where 810 incandescent luminaires are to be installed

Complete Question

What is the minimum number of 20-amp 277-volt branch circuits required where 810 incandescent luminaries are to be installed?The  lamps to be installed are rated 75 watts at 277 volts. This is NOT a continuous load so each circuit can carry 20 amps maximum

The number is  

Explanation:

From the question we are told that

     The current is  

     The voltage is  

     The power rating of each bulb is  

      The total number of  incandescent luminaries is

Generally the amount of current each lamp takes is mathematically represented as

=>    

=>    

Generally the number of bulb fitting(i.e bulbs )  a  20 A current can supply (i.e the bulbs the branch ) to is

=>                

=>                

Generally the number of 20-amp 277-volt branch circuits required is mathematically represented as

=>      

=>      

the ima (higher than 1m) will be greater than the ima with the height of 1m.