Adam's age is a multiple of 9 this year.
His age 6 years ago is a multiple of 4.
Adam's age is between 10 and 20.
- What is Adam's age this year?
- What is Adam's age 5 years ago?
- What is Adam's age 6 years later?
Multiple of 9: 9, 18
Multiple of 9 (-6): 3, 12
Multiples of 4: 4, 8, 12
12 appears in both the multiples of 9 (-6) and the multiples of 4.
(a) Adam's age this year = 18
(b) Adam's age 5 year ago = 18 - 5 = 13
(c) Adam's age 6 years later = 18 + 6 = 24
Answer(s): (a) 18; (b) 13; (c) 24