Problem 3. The father gave 650 denars to his 5 sons and told them to divide them so that each of them receives 30 denars less than the immediately older one. How many denars will each of them receive
Solution. Let the amount of money the youngest son receives be denoted by $x$. Then the other four sons will receive $x+30, x+60, x+90, x+120$. Therefore,

$$
x+x+30+x+60+x+90+x+120=650, \text { i.e. } 5 x+300=650
$$

which means $x=70$. Thus, starting from the youngest, the sons will receive $70,100,130,160,190$ denars respectively.