Question 1099902
NOTE: 
Watts and megawatts are measures of power (the rate/speed at which energy is used or delivered).
That means that people are billed for the amount of energy used in {{{kilowatt*hour}}} . That is power multiplied by time.
My electric bill is in kilowatt-hour in the USA,
y era en kilovatios-hora cuando yo vivía en Sudámerica.
 
An increase of 4% per year meas that as a 4% of the previous cost is added,
the new cost becomes 100% + 4% = 104% of what it was before.
In other words, cost gets multiplied times {{{104/100=1.04}}} every year.
Starting at {{{30 pesos}}} per unit of energy,
after 5 years it would be
{{{(30pesos)*1.04*1.04*1.04*1.04*1.04=(30pesos)*1.04^5=(30pesos)*1.04^5=(30pesos)*1.2166529024=36.499587072pesos}}} .
I would round that to {{{36pesos}}} , because 36.499587072 is less than 36.50.