Increased energy efficiency ultimately leads to lower costs.

True.  Use of new technology or methods to increase energy efficiency will lead to less energy consumption.  This in turns will lower the costs because power is now used to do a variety of things without having to exert too much of it.

the answer is T in e2020

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

truck y has a greater velocity than truck x.