10ticks Friday Puzzle

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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!

See the latest Friday Puzzle below and look at all the past puzzles. Get the Friday Puzzle straight to your phone, follow us on Twitter. The first 5 correct answers join our Hall of Fame!

This week's Friday Puzzle

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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Friday Puzzle (08/09/2017)

open grid

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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Friday Puzzle (01/09/2017)


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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Friday Puzzle (25/08/2017)

table of numbers

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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Friday Puzzle (18/08/2017)

Each letter stands for a different digit.
So if A = 7 and B = 3,   AB would mean 73   and    AB = 7 cubed.

If AY = IS, AD = 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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Friday Puzzle (11/08/2017)

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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Friday Puzzle (21/07/2017)

Use 3D co-ordinates to find the distance between (1, 1, 1) and (4, 5, 13).

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Friday Puzzle (14/07/2017)

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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Friday Puzzle (07/07/2017)

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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Friday Puzzle (30/06/2017)

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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