If the output is 89 what is the input

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Tyler enjoys the fish so much that after his birthday his family decides to take him to a famous aquarium a tank at the aquarium is similar to his tank with the scale factor of 8 how many times greater is the volume of the tank at the aquarium than the volume of tyler tank

If olu is twice as old as funmi if the sum of their ages is 60 how old is olu