Adam's age is a multiple of 5 this year.
His age next year will be multiple of 9.
Adam's age is between 30 and 40.
- In how many years' time will Adam's age be a multiple of 3?
- How many years ago was Adam's age a multiple of 6?
(a)
Multiples of 5 (between 30 and 40): 30, 35, 40
Multiples of 5 (+1): 21, 26, 31, 36, 41
Multiples of 9: 36
Adam's age next year: 36Adam's age this year: 35Multiples of 3: 21, 24, 27, 30, 33, 36, 39
Adam's age when it becomes a multiple of 3 = 36
Number of years' time when Adam's age will be a multiple of 3
= 36 - 35
= 1
(b)
Multiple of 6: 24, 30
Least number of years ago when Adam's age was a multiple of 6
= 35 - 30
= 5
Answer(s): (a) 1; (b) 5