Adam's age is a multiple of 10 this year.
His age 3 years ago was a multiple of 9.
- What is Adam's age this year?
- What was Adam's age 3 years ago?
- What is Adam's age 5 years later?
Multiple of 10: 10, 20, 30
Multiple of 10 (-3): 7, 17, 27
Multiple of 9: 9, 18, 27
27 appears in both the multiples of 10 (-3) and the multiples of 9.
Adam's age 3 years ago = 27
(a) Adam's age this year = 30
(b) Adam's age 3 year ago = 30 - 3 = 27
(c) Adam's age 10 years later = 30 + 5 = 35
Answer(s): (a) 30; (b) 27; (c) 35