Admission test for the degree course in medicine and surgery 2012-2013
Domanda 15 di 80
The 100W light bulb (cost €0.60) is not going to be used anymore and is being replaced with the 20W (cost €3) low energy light bulb. If electricity is charged at €0.15 per kWh, for how many hours must the low energy bulb be used in order for the lower cost of running it to exactly compensate for its higher initial cost?