Adam's age is a multiple of 5 this year.
His age 4 years ago was a multiple of 9.
- What is Adam's age this year?
- What was Adam's age 10 years ago?
- What is Adam's age 8 years later?
Multiple of 5: 5, 10, 15, 20, 25, 30, 35, 40
Multiple of 5 (-4): 1, 6, 11, 16, 21, 26, 31, 36
Multiple of 9: 9, 18, 27, 36
36 appears in both the multiples of 5 (-4) and the multiples of 9.
Adam's age 4 years ago = 36
(a) Adam's age this year = 40
(b) Adam's age 10 year ago = 40 - 10 = 30
(c) Adam's age 5 years later = 40 + 8 = 48
Answer(s): (a) 40; (b) 30; (c) 48