Adam's age is a multiple of 7 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 10?
- How many years ago was Adam's age a multiple of 3?
(a)
Multiples of 7 (between 30 and 40): 35
Multiples of 7 (+1): 22, 29, 36
Multiples of 9: 36
Adam's age next year: 36Adam's age this year: 35Multiples of 10: 20, 30, 40
Adam's age when it becomes a multiple of 10 = 40
Number of years' time when Adam's age will be a multiple of 10
= 40 - 35
= 5
(b)
Multiple of 3: 21, 24, 27, 30, 33
Least number of years ago when Adam's age was a multiple of 3
= 35 - 33
= 2
Answer(s): (a) 5; (b) 2