A HOTEL HAS TEN ROOMS ALONG EACH SIDE OF A CORRIDOR. AN OLYMPIAD• E...

3. A hotel has ten rooms along each side of a corridor. An olympiad

• Each question carries 10 marks. However, earlier

team leader wishes to book seven rooms on the corridor so that no

questions tend to be easier. In general you are

two reserved rooms on the same side of the corridor are adjacent. In

advised to concentrate on these problems first.

how many ways can this be done?

• The use of rulers, set squares and compasses

is allowed, but calculators and protractors are

forbidden.