Adam's age is a multiple of 9 this year.
His age 8 years ago was a multiple of 10.
- What is Adam's age this year?
- What was Adam's age 6 years ago?
- What is Adam's age 3 years later?
Multiple of 9: 9, 18
Multiple of 9 (-8): 1, 10
Multiple of 10: 10
10 appears in both the multiples of 9 (-8) and the multiples of 10.
Adam's age 8 years ago = 10
(a) Adam's age this year = 18
(b) Adam's age 6 year ago = 18 - 6 = 12
(c) Adam's age 9 years later = 18 + 3 = 21
Answer(s): (a) 18; (b) 12; (c) 21