Adam's age is a multiple of 3 this year.
His age next year will be multiple of 4.
Adam's age is between 30 and 40.
- In how many years' time will Adam's age be a multiple of 5?
- How many years ago was Adam's age a multiple of 5?
(a)
Multiples of 3 (between 30 and 40): 30, 33, 36, 39
Multiples of 3 (+1): 22, 25, 28, 31, 34, 37, 40
Multiples of 4: 32, 36, 40
Adam's age next year: 40Adam's age this year: 39Multiples of 5: 20, 25, 30, 35, 40
Adam's age when it becomes a multiple of 5 = 40
Number of years' time when Adam's age will be a multiple of 5
= 40 - 39
= 1
(b)
Multiple of 5: 20, 25, 30, 35
Least number of years ago when Adam's age was a multiple of 5
= 39 - 35
= 4
Answer(s): (a) 1; (b) 4