[tex]\huge\ \star\;{\underline{\underline{\pmb{\mathfrak{Answer:}}}}}[/tex]
[tex]\ \star\;{\underline{\underline{\pmb{\mathtt{Adam=13~ Adam's~ mother = 39}}}}}[/tex]
When Adam was born, his mother was 26 years old. Let's denote Adam's age when he was 3 times younger than his mother as A.
So, at that time, Adam's age was 1/3 of his mother's age.
Adam's mother's age at that time would be A + 26.
According to the given condition, Adam's age at that time (A) is 1/3 of his mother's age (A + 26):
[tex]\tt{A~ = ~1/3 ~× (A + 26)~ }[/tex]
Now, we can solve for A:
[tex]\tt{3A~ = ~A ~+~ 26~ }[/tex]
[tex]\tt{3A~ - ~A ~= ~26~ }[/tex]
[tex]\tt{2A ~=~ 26~ }[/tex]
[tex]\tt{★ A~=~13 }[/tex]
So, Adam was 13 years old when he was 3 times younger than his mother.