Adam's age is a multiple of 8 this year.
His age 7 years ago was a multiple of 7.
Adam's age is between 50 and 60.
- 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 5?
(a)
Multiple of 8: 8, 16, 24, 32, 40, 48, 56
Multiple of 8 (-7): 1, 9, 17, 25, 33, 41, 49
Multiples of 7: 7, 14, 21, 28, 35, 42, 49
Adam's age this year = 56
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48, 54, 60
Number of years' time when Adam will be a multiple of 6
= 60 - 56
= 4
(b)
Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55
Least number of years ago when Adam's age was a multiple of 5
= 56 - 55
= 1
Answer(s): (a) 4; (b) 1