Answer:
Jenny´s age is 19 and her mother is 43.
Explanation:
1. Plug in the first value of the set:





41 is different from 62, so Jenny isn´t 12 years old.
2. Plug in the second value of the set:





50 is different from 62, so Jenny isn´t 15 years old.
3. Plug in the third value of the set:





59 is different from 62, so Jenny isn´t 18 years old.
4. Plug in the fourth value of the set:





Therefore Jenny´s 19 years old.
5. Calculate Jenny´s mother age:
As the sum of their ages is 62 ages, we have the following equation:

where
x=Jenny´s age
y=Jenny´s mother age
Replacing the Jenny´s age we have:

Solving for y:


Therefore Jenny's mother age is 43 years old.