Today Puzzle #699
Puzzle No. 699 鈥� Wednesday 18 March
At a meeting of coin collectors, every person has a collection of ten and twenty pence coins. Each person’s coins add to give a total of one pound. If no two people brought the same combination of 10p and 20p coins, what is the largest possible number of people at the meeting?
Today’s #PuzzleForToday has been set by Dr Steve Humble from Newcastle University
Click here for the answer
There could be 4 coin collectors at the meeting with a combination of 10p and 20p coins. There could be six at the meeting if we count the possibly that a coin collector does not have one of the types of coins.
Details of a possible solution.
10X + 20Y = 100
Hence we can write X = 10 – 2Y and look for integer solutions
(Y can take integer values of 0, 1, 2, 3, 4, 5)
-
![]()
Puzzle for Today 鈥� Index
Find all of the currently available Puzzles for Today, with answers.
More fiendish brain-teasers and quizzes on 大象传媒 Radio...
-
![]()
From autumn leaves to the magic roundabout: test yourself with our favourite quizzes.
-
![]()
We asked the intelligence agency to set our listeners a code-cracking challenge... Can you solve it?
-
![]()
Quiz: How many of these Mastermind music questions can you answer?
Here's a chance to find out whether your specialist subject on Mastermind could be the entire history of music.
-
![]()
Six conundrums to grapple with, including the Riddle of the Sphinx. Try not to forfeit your life...
