I would really appreciate help with how to explain the following question which appears in the 2008 MGS paper ( Paper 2 )
A newspaper is made up from double sheets of paper, placed on top of each other, and then folded down the middle.
For example, an 8-page newspaper is made from two double sheets. The outer one consists of the pages numbered 1, 2, 7 and 8. The inner one, which is tucked inside the outer, consists of the pages numbered 3, 4, 5 and 6.
(a) In a 16-page newspaper, what other three numbers are on the double sheet with page 3 on it?
(b) In a 24-page newspaper, what other three numbers are on the double sheet with page 18 on it?
(c) In another newspaper, pages 7 and 42 are on the same double sheet. How many pages does this newspaper have?
I know there must be an easier way of explaining this without having to draw out the pages, but I'm lost right now.
Practical learning as suggested by moved is great fun, and will help retain the concepts for much longer time.
Another way of solving is to write page numbers in two rows : Front to Back, and Back to Front
Front to Back : 1, 2,
3, 4, 5, 6
, ….…….19, 20,
21, 22, 23, 24
Back to Front : 24, 23,
22, 21, 20, 19,
4 3, 2, 1
Each double sheet has four pages :2 pages from front to back, and 2 pages back to front - as underlined above.