Oliver's age is a multiple of 9 this year. His age next year will be a multiple of 8. Oliver is more than 60 years old. What is Oliver's age this year?
Multiples of 9: 9, 18, 27, 36, 45, 54, 63
Multiples of 9 (+1): 10, 19, 28, 37, 46, 55, 64
Multiples of 8: 8, 16, 24, 32, 40, 48, 56, 64
Common number = 64
Oliver's age this year
= 64 - 1
= 63
Answer(s): 63