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


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


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


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