there are 4 pens in each pack of black pens, 5 in a pack of red pens and 6 in a pack of green pens on monday 7:3:4 pens were sold. a total of 268 pens were sold work out the number of red pens sold

The john nash mall used 17,4000 kilowatt hours in may, with a peak load of 92 kilowatts. the demand charge is $5.95 per kilowatt, and the energy charge is $0.08 per kilowatt hour. the fuel adjustment charge is $0.017 per kilowatt hour. what is the total electricity cost for may?