Thinking Skills: Critical Thinking and Problem Solving

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.