Let
C=Cynthia's age today
A=Abigail's age today
then
at all times
A=C+8......................(1)
twenty years ago,
A-20=3(C-20)
simplifying
A=3C-40...................(2)
Equate (1) and (2),
C+8=3C-40
8+40=3C-C
C=24
=>
A=32
Check: A-C=8... ok A-20=12 C-20=4 => (A-20)=3(C-20) ...ok
Answer:
Abigail is 32, Cynthia is 24.
