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 probabilty, 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


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


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