## 238. Math Puzzle $3 / 85$

The new cultural room of a company is looking forward to its completion. The lighting in such rooms has a significant influence on the coziness. After extensive consultations, it is decided to install 50 individual light sources with relatively low power.

How many 40-watt and how many 75-watt lamps will be used if the room is to be illuminated with a total power of 3050 watts?
1) $40 x+75 y=3050$; 2) $x+y=50$ results in solving and substituting $y=30 ; x=20$. Twenty 40-W lamps and thirty 75-W lamps are used.