The Ultimate Mathematical Challenge: Over 365 puzzles to test your wits and excite your mind. Литагент HarperCollins USD

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The Ultimate Mathematical Challenge: Over 365 puzzles to test your wits and excite your mind - Литагент HarperCollins USD

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£250 000. Rein Beau usually spends his day in the small stable, but when he wandered across into the large stable, Mr Gallop was surprised to find that the average value of the ponies in each stable rose by £10 000.

      What is the total value of all six ponies?

       [SOLUTION]

      122. Making a square

      I have two types of square tile. One type has a side length of 1 cm and the other has a side length of 2 cm.

      What is the smallest square that can be made with equal numbers of each type of tile?

       [SOLUTION]

      123. How many pairs?

      How many pairs of digits (p, q) are there so that the five-digit integer ‘p869q’ is a multiple of 15?

       [SOLUTION]

      124. What is the product?

      Lucy wants to put the numbers 2, 3, 4, 5, 6 and 10 into the circles so that the products of the three numbers along each edge are the same, and as large as possible.

image

      In how many ways can this be done?

       [SOLUTION]

      125. A five-team league

      Five teams played in a competition and every team played once against each of the other four teams. Each team received three points for a match it won, one point for a match it drew and no points for a match it lost.

      At the end of the competition the points were as follows:

Yellows 10
Reds 9
Greens 4
Blues 3
Pinks 1

      How many of the matches resulted in a draw?

      What were the results of the Greens’ matches against the other teams?

       [SOLUTION]

      126. A mini crossnumber

      The solution to each clue of this crossnumber is a two-digit number, not beginning with zero.

image

       Across

       1. A triangular number

       3. A triangular number

       Down

       1. A square

       2. A multiple of 5

      In how many different ways can the crossnumber be completed correctly?

       [SOLUTION]

      See Shuttle Challenge 1 for how the Shuttle works.

       Question 1

      What is the value of image?

       Question 2

      [A is the answer to Question 1.]

      The number A is an example of a palindromic integer – one that is unchanged when the order of its digits is reversed.

      How many palindromic integers are there from 300 to A inclusive?

       Question 3

      [A is the answer to Question 2.]

      The diagram shows a triangle drawn on a square grid made up of nine smaller squares.

image

      The area of the shaded triangle is A cm2.

      What is the area, in cm2, of one of the smaller squares?

       Question 4

      [A is the answer to Question 3.]

      Write the number A as a word in the gap shown in the following sentence.

      Out of the first __________ letters in this sentence, what fraction is vowels?

      Now answer the question.

       [SOLUTION]

      127. Coins in a frame

      The diagram shows 10 identical coins that fit exactly inside a wooden frame. As a result, each coin is prevented from sliding.

image

      What is the largest number of coins that may be removed so that each remaining coin is still unable to slide?

       [SOLUTION]

      128. Cheetah v. snail

      In a sponsored ‘Animal Streak’, the cheetah ran at 90 kilometres per hour, while the snail slimed along at 20 hours per kilometre. The cheetah kept going for 18 seconds.

      Roughly how long would the snail take to cover the same distance as the cheetah?

       [SOLUTION]

      129. Memorable phone numbers

      A new taxi firm needs a memorable phone number.

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