Adam's age is a multiple of 9 this year.
His age 7 years ago was a multiple of 8.
Adam's age is between 60 and 70.
- In how many years' time will Adam's age be a multiple of 6?
- How many years ago was Adam's age a multiple of 8?
(a)
Multiple of 9: 9, 18, 27, 36, 45, 54, 63
Multiple of 9 (-7): 2, 11, 20, 29, 38, 47, 56
Multiples of 8: 8, 16, 24, 32, 40, 48, 56
Adam's age this year = 63
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66
Number of years' time when Adam will be a multiple of 6
= 66 - 63
= 3
(b)
Multiples of 8: 8, 16, 24, 32, 40, 48, 56
Least number of years ago when Adam's age was a multiple of 8
= 63 - 56
= 7
Answer(s): (a) 3; (b) 7