Adam's age is a multiple of 9 this year.
His age 4 years ago was a multiple of 7.
- What is Adam's age this year?
- What was Adam's age 10 years ago?
- What is Adam's age 3 years later?
Multiple of 9: 9, 18
Multiple of 9 (-4): 5, 14
Multiple of 7: 7, 14
14 appears in both the multiples of 9 (-4) and the multiples of 7.
Adam's age 4 years ago = 14
(a) Adam's age this year = 18
(b) Adam's age 10 year ago = 18 - 10 = 8
(c) Adam's age 9 years later = 18 + 3 = 21
Answer(s): (a) 18; (b) 8; (c) 21