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 

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

Sunday Afternoon Maths LXV

Cryptic crossnumber #1
Breaking Chocolate
Square and cube endings

List of all puzzles


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


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2019