Ten machines use 200 kilowatts to operate for 5 days, 10 hours per day. Determine the number of kilowatts used if they work for 3 days, 8 hours per day?
and the answer has to be in kW
updated
would it be
200kw /130hrs = x/80hrs
1600/130 = 130x
123= x
I did fractions with cross multiplying and got x= 71.4 kW but I know I am wrong.
5/3 + 10/8 = 200 kW/ x
40/24 + 30/42 = 200kW/ x
70/24 = 200kW/ x
70x = 5000 kW/70
x= 71.4 kW
The unit of energy is the kilowatt-hour or some such. Kilowatts are a measure of power. As such, the duration of operation does not matter. If ten machines use $200$ kW, they use $200$ kW no matter how long they run. It is possible the point of the problem is for you to notice the difference between kilowatts and kilowatt-hours.
If the problem means $200$ kWh for $10$ machines, $5$ days, $10$ hours/day, that is $50$ hours of operation, so a $4$ kW power level. $3$ days, $8$ hours/day is $24$ hours, so they would consume $96$ kWh.