Mark's age is a multiple of 7 this year. His age next year will be a multiple of 8. Mark is more than 60 years old. What is Mark's age this year?
Multiples of 7: 7, 14, 21, 28, 35, 42, 49, 56, 63
Multiples of 7 (+1): 8, 15, 22, 29, 36, 43, 50, 57, 64
Multiples of 8: 8, 16, 24, 32, 40, 48, 56, 64
Common number = 64
Mark's age this year
= 64 - 1
= 63
Answer(s): 63
