Can some one provide a step by step guide thanks In a group

Can some one provide a step by step guide thanks.

In a group of 100 adults, 70 say they are most likely to do spring housecleaning in March, April or May. Of these 70, the number who clean in April is 14 more than the total number who clean in March and May. The total number who clean in April and May is 2 more than three times the number who clean in March. Find the number who clean in each month.

Solution

Let the number of adults who clean in march, april and may be x,y and z respectively .

x +y+z=70

y=x+z+14

y+z=3x+2

solving them, we get

x=17, y=42, z=11