mscroggs.co.uk
mscroggs.co.uk

subscribe

Puzzles

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

Archive

Show me a random puzzle
 Most recent collections 

Advent calendar 2023

Advent calendar 2022

Advent calendar 2021

Advent calendar 2020


List of all puzzles

Tags

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

Archive

Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2024