## Task 3 - 210623

Over the course of a year, the number of tables produced in a furniture factory increased by 10 each month. In total, 1920 tables were produced over the entire year.

a) How many tables were produced in the month of June?

b) How many tables were produced in the month of December?
In the operation, 10 more tables were produced in February, 20 more in March, ..., 50 more in June, ..., and 110 more in December compared to January. Due to

$$
10+20+30+40+50+60+70+80+90+100+110=660
$$

this results in a total of 660 more tables being produced compared to if the production increase had not occurred, meaning the same number of tables would have been produced in all 12 months, the same as in January.

Due to $1920-660=1260$ and $1260: 12=105$, 105 tables were thus produced in January.

a) From $105+50=155$ it follows that 155 tables were produced in June.

b) Due to $105+110=215$, 215 tables were produced in December.