The Ultimate Mathematical Challenge: Over 365 puzzles to test your wits and excite your mind

Place the number in the top square of the answer grid and the name in the bottom square of each row.

The clues

Tracey is in the front row in front of Jenny.

The average of the two numbers in the middle of the front row is Sarah’s number, a square.

Peter is not sitting next to a girl.

Steve is sitting between Liz and Jenny.

Players with prime numbers, which includes Alan, are sitting in the front row.

There is only one boy on the end of a row.

In both the front and back rows the two places on the right (as you look at it) are filled by a boy and a girl.

Matthew and Steve have the highest and lowest numbers a boy could wear.

Jenny’s number is three times as large as Tracey’s and twice as large as that of Peter, who is not sitting on the end of a row.

Girls have even numbers.

Back row

Front row

[SOLUTION] (#litres_trial_promo)

Week 3 (#ulink_de5bc97f-d628-5f7b-a856-f997eaea0b93)

15. A line of lamp posts

Four lamp posts are in a straight line. The distance from each post to the next is 25 metres.

What is the distance from the first post to the last?

[SOLUTION] (#litres_trial_promo)

16. Sums of digits

For how many three-digit numbers does the sum of the digits equal 25?

[SOLUTION] (#litres_trial_promo)

17. A million seconds

How many days, to the nearest day, are there in a million seconds?

[SOLUTION] (#litres_trial_promo)

18. Sum to 100

The sum of 10 distinct positive integers is 100. What is the largest possible value of any of the 10 integers?

[SOLUTION] (#litres_trial_promo)

19. x marks the spot

The numbers 2, 3, 4, 5, 6, 7, 8 are to be placed, one per square, in the diagram shown such that the four numbers in the horizontal row add up to 21 and the four numbers in the vertical column also add up to 21.

Which number should replace x?

[SOLUTION] (#litres_trial_promo)

20. The last Wednesday

One of the months in a particular year has five Wednesdays, and the third Saturday is the 19th.

Which day of the month is the last Wednesday?

[SOLUTION] (#litres_trial_promo)

21. Her brother’s age

A woman says to her brother, ‘I am four times as old as you were when I was the same age as you are now.’

The woman is 40 years old.

How old is her brother now?

[SOLUTION] (#litres_trial_promo)

Week 4 (#ulink_cdf24422-70e9-5513-8bf6-454eb7dc2098)

22. Pings and pongs

Five pings and five pongs are worth the same as two pongs and eleven pings.

How many pings is a pong worth?

[SOLUTION] (#litres_trial_promo)

23. How many sides?

A single polygon is made by joining dots in the grid with straight lines, which meet only at dots at their end points. No dot is at more than one corner. The diagram shows a five-sided polygon formed in this way.

What is the greatest possible number of sides of a polygon formed by joining the dots using these same rules?