Adam's age is a multiple of 9 this year.
His age 3 years ago was a multiple of 5.
- What is Adam's age this year?
- What was Adam's age 7 years ago?
- What is Adam's age 9 years later?
Multiple of 9: 9, 18
Multiple of 9 (-3): 6, 15
Multiple of 5: 5, 10, 15
15 appears in both the multiples of 9 (-3) and the multiples of 5.
Adam's age 3 years ago = 15
(a) Adam's age this year = 18
(b) Adam's age 7 year ago = 18 - 7 = 11
(c) Adam's age 9 years later = 18 + 9 = 27
Answer(s): (a) 18; (b) 11; (c) 27