Welcome to Ian’s Friday Puzzle! Dust off those Friday cobwebs with a little manipulation of the old grey matter. Perplexing puzzles, logical, illogical, and sometimes just plain stupid. Be prepared to be bewildered, befuddled and bedazzled!

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A cuboid fish tank is tilted so the water is reaching the top edge and the midpoint of the base as shown.

What is the depth of the water in the tank when the tank is returned to a horizontal position?

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Only the numbers 1, 2, 3, and 4 are used.

Each row and column add to the number shown.

No numbers are repeated in any row or column.

Complete the grid.

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Two congruent equilateral triangles overlap so that the area of the overlap (shaded yellow) equals half of either of the other two areas.

Which is longer, AB or CB?

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From the box choose pairs of numbers that:

add up to 15,

add up to 25,

add up to 35,

add up to 45.

What is the odd number out?

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Each letter stands for a different digit.

So if A = 7 and B = 3, AB would mean 73 and A^{B} = 7 cubed.

If A^{Y} = IS, A^{D} = SA and (IS)^{Y} = YES, find the values for A, E, I, S, Y.

What is (YES)^{Y} ?

Hint: for the garden!

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8 can be written as the sum of two prime numbers.

8 = 3 + 5.

How many whole numbers less than 20 cannot be written as the sum of two prime numbers?

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47.5 + 3862.7 + 125.6 + 1583.1 = 45085.7

I got this wrong! When I did the calculation I forgot all about decimal places.

In fact the decimal point is only correct in one of the numbers.

Which one?

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Jolly good show. This is a capital question, what!

5 and 9 are the first two numbers like this. Find me another FOUR.

There are another fourteen.

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In the hexagon, find the largest right-angled triangle and the smallest right-angled triangle.

What is the ratio of the area of the largest right-angled triangle to the area of the smallest right-angled triangle

in the hexagon?

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