Exercise 1

Calculate, what is the ratio  of the crude oil among all the sources of energy.

Exercise 2

There is a plan to increase the production of energy out of renewable sources next year.

It is known, the amount of energy from these sources will be increased by 1/3 of today’s production from the solid fuel. After this increase, is it going to be more than production out of the crude oil and the gas together?

Exercise 3

If 57,50% of Polish sources of energy are the solid fuel, which source of energy is 11,5 times lower?

Exercise 4

Solar collectors cost 1200 PLN, average mothly bill for heating amounts to 320 PLN, solar collectors cover 25% of monthly demand of energy for heating. How much will we save by using solar collectors during 6 months?