# Puzzles

## Archive

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#### Sunday Afternoon Maths LXVII

Coloured weightsNot Roman numerals

#### Advent calendar 2018

#### Sunday Afternoon Maths LXVI

Cryptic crossnumber #2#### Sunday Afternoon Maths LXV

Cryptic crossnumber #1Breaking Chocolate

Square and cube endings

List of all puzzles

## Tags

differentiation squares coordinates logic probability taxicab geometry addition colouring folding tube maps percentages cube numbers sum to infinity speed number star numbers odd numbers dodecagons perimeter remainders planes complex numbers sums cryptic clues area prime numbers chess advent 3d shapes menace irreducible numbers quadratics averages chalkdust crossnumber crosswords palindromes arrows sequences polygons integers cryptic crossnumbers algebra perfect numbers indices games triangle numbers coins shape division scales partitions multiples bases calculus grids dates triangles money numbers hexagons wordplay books mean people maths unit fractions ave cards multiplication doubling functions routes integration square numbers christmas proportion time means 2d shapes floors geometry factorials balancing probabilty square roots rectangles digits angles dice shapes regular shapes surds lines factors pascal's triangle volume sport symmetry spheres graphs clocks ellipses chocolate trigonometry parabolas fractions rugby circles crossnumbers## The ace of spades

I have three packs of playing cards with identical backs. Call the packs A, B and C.

I draw a random card from pack A and shuffle it into pack B.

I now turn up the top card of pack A, revealing the Queen of Hearts.

Next, I draw a card at random from pack B and shuffle it into pack C. Then, I turn up the top card of pack B, revealing another Queen of Hearts.

I now draw a random card from pack C and place it at the bottom of pack A.

What is the probability that the card at the top of pack C is the Ace of Spades?

## Whist

Messrs. Banker, Dentist, Apothecary and Scrivener played whist last night. (whist is a four player card game where partners sit opposite each other.) Each of these gentlemen is the namesake of another's vocation.

Last night, the apothecary partnered Mr. Apothecary; Mr. Banker's partner was the scrivener; on Mr. Scrivener's right sat the dentist.

Who sat on the banker's left?