 We have an old air conditioner with an EER of 6. EER of 6. And EER is basically energy efficiency ratio, which is given by number of BTUs the air conditioners pulling out per hour divided by watts of power it consumes. And in this problem, we are given the EER as 6. And we need to calculate the BTUs it's capable of pulling out. We also know that it is consuming 1,000 watts of power. So we need to calculate these BTUs per hour that it is pulling out. So we can calculate that x unknown by multiplying 1,000 by 6, and we get 6,000 BTUs per hour. The room size is not changing, but we are just replacing the old air conditioner with a new one. The new EER is 10. The new air conditioner EER is 10. And it is still pulling 6,000 BTUs per hour out. The new one, how many watts of power does it consume? To calculate the power, we have 6,000 BTUs per hour load. And we know the EER that is 10. So dividing by this, we get the power that is 600 watts. What we are doing here is by replacing the old air conditioner, which used to consume 1,000 watts, by this new air conditioner, which has an EER of 10, we are reducing the power consumption to 600 watts.