Adam's age is a multiple of 9 this year.
His age 2 years later will be multiple of 10.
- What is Adam's age this year?
- What was Adam's age 8 years ago?
- What is Adam's age 5 years later?
Multiple(s) of 9: 9, 18
Multiple(s) of 9 (+2): 11, 20
Multiple(s) of 10: 10, 20
20 appears in both the multiples of 10 and the multiples of 9 (+2).
20 is Adam's age 2 years later.
(a) Adam's age this year = 18
(b) Adam's age 8 year ago = 18 - 8 = 10
(c) Adam's age 9 years later = 18 + 5 = 23
Answer(s): (a) 18; (b) 10; (c) 23