by David, 14 November 2018 | 0 comments

At half-past three, what is the angle between the hands of a clock? Scroll down for the answer! Brainteaser answer First, a quick estimate. The short hand points across to the three, and the long hand points straight down to the 6. The angle is about 90 degrees, but there’s a more accurate…

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by David, 31 October 2018 | 1 comments

Jenny had a short, wide fish tank. She wanted to change the water, so she put the fish tank on a table and put a tall bucket on the floor right underneath. She was about to get a hose and siphon the water into the bucket, but before she started, she did some measuring. It…

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by David, 17 October 2018 | 0 comments

Tom’s just finished sewing a quilt! It’s made of lots of equal-sized squares of fabric sewn together. Currently, it’s 12 squares long and six squares wide. Tom tried putting the quilt on his bed, but it’s the wrong shape. He’s decided to make it nine squares long and eight squares wide. Tom wants to break…

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by David, 3 October 2018 | 0 comments

Australia has six coins that are commonly used – 5 cents, 10 cents, 20 cents, 50 cents, $1 and $2. How many different ways can you make exactly 50 cents in Australian coins?

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by David, 19 September 2018 | 0 comments

On Sunday, 1 January, Latda announced her New Year’s resolution. “Throughout this year, on the fifth Sunday of the month, I’ll throw a party!” How many fifth Sunday parties did Latda celebrate that year?

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by David, 5 September 2018 | 0 comments

Peter’s just finished building a new staircase up to the attic. It just fits along the four-metre-long wall of his lounge room, and it’s three metres tall. It has exactly 15 steps. Peter wants to have a carpet running along the staircase. How long does it need to be?

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by David, 21 August 2018 | 0 comments

Can you work out the next letter in this sequence? H, T, Q, F, S, S, E, N, … Hint: There are numbers lurking behind those letters. And as it grows, this sequence is shrinking!

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by David, 8 August 2018 | 4 comments

Imagine your calculator is broken. Although it will still display numbers, only the 4 key, + key, = key and clear key work. Starting at 0, can you get the calculator to display 1000? What’s the fastest way, with the fewest button presses?

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by David, 25 July 2018 | 1 comments

Twenty years ago, my mum was twice my age. I’m 42 years old. How old is my mum?

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by David, 11 July 2018 | 0 comments

Tomas is putting a number on a letterbox. He puts on one digit. Then he adds another digit. Tomas looks at it and notices that it makes a number exactly five times the first digit. Tomas adds a third and final digit. Once again, Tomas looks at the number and notices that the three digit…

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