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?

Show answer

If you enjoyed this puzzle, check out Sunday Afternoon Maths XXVIII,
puzzles about cards, or a random puzzle.


Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020