The formula would be: X(X+1)=6162.
X^2+X = 6162.
X^2+X-6162 = 0; Factor this.
(X+79)(X-78)=0.
X+79=0 or X=-79; impossible.
X-78=0; X=78; first page.
Second page X+1=79.
Therefore page numbers are 78 & 79.
Check: 78*79=6162.
The two page numbers are 64 and 65. 64 x 65 = 4160.
52 and 53
If one of the pages is numbered p, the other is p+1. So p*(p+1) = 420 That is, p2 + p - 420 = 0 which factorises as (p - 20)*(p + 21) = 0 That implies that p = 20 or p = -21. Assuming that pages do not have negative numbers, p = 20 and then the other page is p+1 = 21.
The solution is: Let X = left page and X+1 = right page. X + (X+1) = 89. Solve for X; X = 44 which is left page and right page is X+1 = 45.
pages 56 and 57
The book is opened to pages 26, on the left, and 27, on the right. The product of 26 times 27 is 702.
The book is open to page 24, on the left, and 25, on the right. The product of 24 times 25 is 600.
Square root of 1056 is about 32½, so the pages must be 32 and 33.
The two page numbers are 64 and 65. 64 x 65 = 4160.
40 & 41
They are 44 and 45.
They are pages 42 and 43 because the product of both numbers is 1806
17 and 18
122 and 123How?|vif the page is double sided then it has two numbers that are added... divide 245 by 2 and you get 122.5 so one page is pg. 122 and the other is pg. 123
Facing the Future has 160 pages.
52 and 53
If one of the pages is numbered p, the other is p+1. So p*(p+1) = 420 That is, p2 + p - 420 = 0 which factorises as (p - 20)*(p + 21) = 0 That implies that p = 20 or p = -21. Assuming that pages do not have negative numbers, p = 20 and then the other page is p+1 = 21.