Logic Puzzles by the Dozen Volume II

The Everything Logic Puzzles Book, Volume 2

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Play Kenken online here. You can choose the size of the game, operations, and the difficulty level. Kakuro puzzles are "cross-sum" puzzles—like mathematical crossword puzzles. Each "word" must add up to the number provided in the clue above it or to the left. Download 5x5 Kakuro puzzles at KrazyDad. Other sizes exist also. Challenging puzzles sent to my puzzle contest.

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It is divided into 14 chapters, each with different kinds of puzzles, such as matchstick puzzles, dominoes and dice, divisibility, cross sums and magic squares, "Measure Seven Times Before You Cut" dissection puzzles , "With Algebra and without It" tricky word problems , and so on.

The puzzles and brainteasers range from simple fun riddles to difficult problems, yet none requiring advanced math.

They are almost always illustrated and often presented as amusing stories. The book was originally published in Russia in Martin Gardner has edited the book to make it as easy as possible for an English-reading public to understand, while carefully retaining nearly all the warmth and humor of the original. Bedtime Math Fun and lively daily math problems centered around real-life topics and offered in three levels: You can also get Bedtime Math problems in a free app. Sally's Hexagon Number Puzzles These are "number pyramids" where you get each number by adding the numbers just below it.

Puzzles increase in difficulty so that grade 4 puzzles use negative numbers and grade 5 puzzles use decimals. Most are visual kind of puzzles where you rearrange pennies and sticks into another shape. MathMania A children's magazine that is packed full of puzzles, mazes and teasers specially created to appeal to kids ages 7 and up. Matchstick Puzzles A large collection of puzzles where you need to rearrange matches. Chess Snake Puzzles You draw a snake or a path on a 5x5 grid from the lower left square to the upper right square.

The grid has some chess pieces, and each piece attacks the same number of segments of the snake. Math Riddles Fun riddles based on math concepts. Favorite math puzzles for kids.

Can YOU solve the children's maths puzzle that's leaving adults baffled?

Farmer Brown and Farmer Green were ruminating one day on the fence between their farms. Farmer Brown says, "You know I was just thinking. If you gave me one of your cows, then we would have the same number of cows. Click here for the answer Farmer Brown has five and Farmer Green has seven cows.

I have more than two animals at home. All of them are dogs, except for two. All of them are cats, except for two. All of them are hamsters, except for two. What kinds of animals and how many of each animal do I have? See the answer I have three animals: A brick weighs one kilogram plus half of the brick. What is the weight of one brick? Here is the answer It weighs 2 kg. Since half a brick weighs 1 kg, the brick weighs 2 kg. A car is going up a hill.

The hill is one mile long. The driver goes up the hill at an average speed of 30 miles per hour. When the driver reaches the top of the hill, he starts down the other side. The downhill side is also one mile long. How fast must the driver go down the hill in order to average 60 miles per hour? Solution It is impossible to average 60 miles per hour. An average speed of 60 miles per hour requires two minutes to cover two miles. The first mile was covered at 30 miles per hour.

This means that two minutes were used to travel that mile. Hence there are no minutes left to cover the second mile. There are 7 girls on a bus. Each girl has 7 backpacks. In each backpack, there are 7 big cats. For every big cat there are 7 little cats. How many legs are on the bus, not counting the driver?

BBC Radio 4 - Today - Puzzle for Today

Solution There are a total of 10, legs. Below is what each of them said:.

Since each of them were each given numbers 1 to 5, if Peter was told any of the following numbers, he would be able to tell what the two numbers that were picked were:. Therefore, when Peter said that he did not know the numbers, Sally would be able to know that the product Peter was told had to be 4. There are 4 keys and 4 locks. What is the maximum number of times you need to try the locks so as to match all 4 keys to their locks? If you try 3 keys on the 1 st lock, you will know that the 4 th key is a match. So, you only need a maximum of 3 tries.

Similarly, the 2 nd lock needs a maximum of 2 tries and the 3 rd lock needs only 1 try. In the diagram not drawn to scale , the sloping line divides the area of the rectangle in the ratio 1: What is the ratio a: We know that the ratio of the area of the upper rectangle to the area of the lower rectangle is 2: Since both rectangles have the same width, then a and b must also in the ratio 2: What is the number of times the hour hand and the minute hand of a clock form a right angle with each other between and on the same day?

The times the hour hand and the minute hand of a clock form a right angle with each other between and are approximately at , , , , , , , , , , Note that this happens twice every hour, except between and when it happens only three times and not four times as expected. This is because at exactly the hands form a right angle.

There are Primary 6 students.

The ratio of the number of students who like Science to the number who do not is 5: The ratio of the number of students who like Mathematics to the number who do not is 7: The number of students who like both Science and Mathematics is How many students dislike both Science and Mathematics? My teacher had 3 big boxes of sweets. Each box contained sweets of a different colour. Each pupil was given 5 sweets of two different colours. If each pupil in the class received a different combination of colours, what was the largest possible number of pupils in the class?

Assume the three colours are red, blue and yellow.

There are only 4 different combinations for any two colours. So, for red and blue the combinations are:. Hence, the largest possible number of pupils is If you like puzzles - or are facing the eternal conundrum about what to get a puzzle-lover for Christmas - you may enjoy my latest book, Can You Solve My Problems? Available from the Guardian Bookshop and other retailers. I set a puzzle here every two weeks on a Monday.

If you would like to suggest a puzzle email me.

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