Adam's age is a multiple of 7 this year.
His age 6 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 6 years later?
Multiple of 7: 7, 14, 21
Multiple of 7 (-6): 1, 8, 15
Multiple of 5: 5, 10, 15
15 appears in both the multiples of 7 (-6) and the multiples of 5.
Adam's age 6 years ago = 15
(a) Adam's age this year = 21
(b) Adam's age 8 year ago = 21 - 8 = 13
(c) Adam's age 7 years later = 21 + 6 = 27
Answer(s): (a) 21; (b) 13; (c) 27