Adam's age is a multiple of 9 this year.
His age 7 years ago was a multiple of 5.
- What is Adam's age this year?
- What was Adam's age 8 years ago?
- What is Adam's age 4 years later?
Multiple of 9: 9, 18, 27
Multiple of 9 (-7): 2, 11, 20
Multiple of 5: 5, 10, 15, 20
20 appears in both the multiples of 9 (-7) and the multiples of 5.
Adam's age 7 years ago = 20
(a) Adam's age this year = 27
(b) Adam's age 8 year ago = 27 - 8 = 19
(c) Adam's age 9 years later = 27 + 4 = 31
Answer(s): (a) 27; (b) 19; (c) 31