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


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


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