Adam's age is a multiple of 9 this year.
His age 4 years later will be multiple of 10.
- What is Adam's age this year?
- What was Adam's age 9 years ago?
- What is Adam's age 4 years later?
Multiple(s) of 9: 9, 18, 27, 36
Multiple(s) of 9 (+4): 13, 22, 31, 40
Multiple(s) of 10: 10, 20, 30, 40
40 appears in both the multiples of 10 and the multiples of 9 (+4).
40 is Adam's age 4 years later.
(a) Adam's age this year = 36
(b) Adam's age 9 year ago = 36 - 9 = 27
(c) Adam's age 9 years later = 36 + 4 = 40
Answer(s): (a) 36; (b) 27; (c) 40