Adam's age is a multiple of 9 this year.
His age 5 years ago was a multiple of 10.
- What is Adam's age this year?
- What was Adam's age 4 years ago?
- What is Adam's age 9 years later?
Multiple of 9: 9, 18, 27, 36, 45
Multiple of 9 (-5): 4, 13, 22, 31, 40
Multiple of 10: 10, 20, 30, 40
40 appears in both the multiples of 9 (-5) and the multiples of 10.
Adam's age 5 years ago = 40
(a) Adam's age this year = 45
(b) Adam's age 4 year ago = 45 - 4 = 41
(c) Adam's age 9 years later = 45 + 9 = 54
Answer(s): (a) 45; (b) 41; (c) 54