Math 2022 Question 24
2 marks
Question
Anil’s age is a factor of 48. Seven years ago, his age was a multiple of 5. What is Anil’s age now?
Answer
Anil is 12 now
Explanation
This was one of the questions that really gave me pause.
In math, a factor is a number that divides another number evenly, that is with no remainder.
The factors of 48 are
1, 2, 4, 6, 8, 12, 16, 24, 48
If we are dealing with 7 years ago it means that his age now CANNOT be 1, 2, 4, or 6
I substracted 7 from the remaining numbers
8-7 = 1
12-7 = 5
16-7 = 9
24-7 = 17
48-7 = 41
A multiple is the result of multiplying a number by an integer (not a fraction).
So multiples of 5 less than 48 are 5, 10, 15, 20, 25, 30, 35, 40, 45
The only number where 7 years before is a multiple of 5 is 12. Therefore his age is 12
If you have another way to solve this please let me know below in the comments.
