George opens up a colouring book. The product of the page numbers which face him is 1640. What pages is George looking at? Give your answers in the following format. (Eg 1, 2)
The page numbers must be one more than the other.
Left number = 1 u
Right number = 1 u + 1
Since the number ends with the digit 0, it is either a multiple of 5 or 10. We use the products of multiples of 10 to check.
10 x 10 = 100
20 x 20 = 400
30 x 30 = 900
40 x 40 = 1600
50 x 50 = 2500
60 x 60 = 3600
Since the product is 1640, the product of the two page numbers is near to 1600. One of the factors must be a multiple of 5 or 10.
Using guess and check,
39 x 40 = 1560
40 x 41 = 1640
Two pages that George is looking at: 40, 41
Answer(s): 40, 41
