Kim opened her book and saw two consecutive page numbers. The sum of the two numbers can be divided by 5. Both page numbers are more than 11 but less than 45. The bigger number can be divided by 7. What are the two page numbers in ascending order? (Eg 1, 2)
Smaller page number = 1 u
Larger page number = 1 u + 1
Sum of the 2 numbers
= 1 u + 1 u + 1
= 2 u + 1
The sum (2 u + 1) is divisible by 5.
List of possible sum of the 2 numbers: 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90
The larger number (1 u + 1) is divisible by 7.
List of possible larger page number that is divisible by 7: 7, 14, 21, 28, 35, 42
List of possible smaller page number: 6, 13, 20, 27, 34, 41
Check:
27 + 28 = 55
The two page numbers are 27 and 28.
Answer(s): 27, 28