3.6 Solving problems by searching 101
If 5¢ and 20¢ coins are the same
thickness, how many different heights of
$1 pile could she have?
A 5 B 6 C 10 D 11 E 20
4 In a community centre quiz evening, teams
were awarded five points for a correct
answer, no points for no answer, and minus
two points for an incorrect answer. The
teams marked their own score sheets. I
arrived late and the scores after seven
questions were shown on the board as
follows:
Happy Hunters 28
Ignorant Idlers 18
Jumping Jacks 16
Kool Kats 12
Lazy Lurkers - 1
a One team was clearly not even clever
enough to calculate their score correctly.
Which one was it?
b Are there any scores, other than those
shown above, that would have raised
suspicion?
Answers and comments are on pages 318–19.
2 I recently received a catalogue from a book
club. I want to order seven books from
their list. However, I noticed that their price
structure for postage was very strange:
Number of
items
Cost of post
and packing
1 45¢
2 65¢
3 90¢
4 $1.20
5 $1.50
6 or more $3.20
I decide, on the basis of this, that I will ask
them to pack my order in the number of
parcels that will attract the lowest post and
packing charge. How much will I have to pay?
3 Jasmine has been saving all year for her
brother’s birthday. She has collected all
the 5¢ and 20¢ coins she had from her
change in her piggy bank. She is now
counting the money by putting it into piles,
all containing $1 worth of coins. She
notices that she has a number of piles of
different heights.