Adam's age is a multiple of 4 this year.
His age 7 years ago is a multiple of 7.
Adam's age is between 20 and 30.
- What is Adam's age this year?
- What is Adam's age 3 years ago?
- What is Adam's age 8 years later?
Multiple of 4: 4, 8, 12, 16, 20, 24, 28
Multiple of 4 (-7): -3, 1, 5, 9, 13, 17, 21
Multiples of 7: 7, 14, 21
21 appears in both the multiples of 4 (-7) and the multiples of 7.
(a) Adam's age this year = 28
(b) Adam's age 3 year ago = 28 - 3 = 25
(c) Adam's age 8 years later = 28 + 8 = 36
Answer(s): (a) 28; (b) 25; (c) 36