Cambridge International Mathematics

Challenge #endboxedheading

230 Topics in arithmetic (Chapter 10)

16 After 5 years a house costing$175 000was sold for$240 000. What was the annual rate of

compound growth?

17 Jimmy is driving km to his holiday destination. He drives the first km at a speed of

km per hour, and the next km at a speed of km per hour. Find his average speed for

the journey.

200 100

60 100 100

1 In numbering the pages of a book, 408 digits were used. How many pages has the book?

2 A job can be completed in 8 hours by 5 men working equal amounts. How long would 3 men take

to do the job working at a 3313 %more effective rate?

3 The average pulse rate of a person is 60 beats per minute. How many times does the average

person’s heart beat in an average lifetime of 70 years?

4 In an electrical shop, the manager buys a TV set from the distributor. He then marks the set up

60%. When the set did not sell at this price he put it into a “ 3712 %off” sale. Did he make a profit

or a loss?

5 A10%solution of salt in water means “ 10 grams of salt for every 100 grams of salt water solution”.

You are given 100 grams of a10%solution of salt in water and wish to change it to a30%solution

of salt in water. How many grams of salt would you need to add to the solution?

6 Use 1, 2, 3, .... 9 once each to fill the nine spaces so that,

when the three numbers

² in any row, or

² in any column

are multiplied together, the result matches the number at

the end of the row or column.

7 Complete the following number square so that every row,

column and diagonal adds up to 34.

The missing numbers are 4 , 6 , 7 , 8 , 10 , 11 , 12 , 13 , 14 ,

15.

8 The following is across-numberpuzzle. All of the

answers are numbers. There is only one set of answers

which fits all of the clues. Enough clues are given to

solve the problem.

Down A no clue is necessary

B a multiple of 99

C the square of D across

Across B the sum of the digits of B down

D a prime number

E the result of (A down)+(B across)+(C down)

72

120

42

70 32 162

1

5

2916

3

ABC

D

E

IGCSE01

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y:\HAESE\IGCSE01\IG01_10\230IGCSE01_10.CDR Thursday, 23 October 2008 12:06:19 PM PETER