Problem n° 1 .

Mr Dupont has a gas boiler . In 2009 , he spent 852 € on heating . In 2010, he spent 648 €.

1. How much did he spend per month  en 2009 ?

2 . How much did he spend per month in 2010 ?

3. How much did he save between 2010 and 2009 ?

4. How much did he spend in total during these two years ?

5 . How much did he spend per half-year in 2009 ?

Problem n° 2 .

In France, we use these energy sources to produce electricity :

nuclear energy                                     84.2 %

gas                                                        3.2 %

coal                                                       3.7 %

hydraulic energy                                   5.7 %

oil                                                          1.5 %

other renewable energy sources          1.7%

1. What energy source is used the most ?

2. What are the three energy sources that are used the  most ?

3. What energy sources is used the least ?

4 . Put the energy sources in order from the most used to the least used .

5 . How much do nuclear energy and hydraulic energy account for ?