Puzzle of the Week #70 - Divisibility Test

It is easy to test a number for divisibility by 2, 5 or 10, by just looking at the final digit. Divisibility by 3 or 9 is almost as easy, whereby you add together the digits of your number, and if the resulting total (which will necessarily be smaller than your original number) is divisible by 3 (or 9), then so was your original number.

But can you devise a test for divisibility by 7, 11 or 13 (the same procedure for all three) where you can very simply, using addition and subtraction, reduce a number of however many digits, down to a three digit number, which will be divisible by 7, 11 or 13, if and only if your original number was?

Puzzle of the Week #67 - Ten Pin Bowling

This game uses all 100 scrabble tiles drawn at random, including the two blanks (which can represent any letter of your choosing).

The scoring system is the same as that of real ten-pin bowling: you get points for each word, equal to how many letters in the word.

In addition, there are bonus points available as follows:

If you get a spare (use all letters in one frame using two words), you get bonus points equal to the next word you score.

If you get a strike (a ten letter word), you get bonus points equal to the next two words you score.

If you only get one word in a frame, and it's not a strike, then for the purposes of bonus points, you get a zero length word too.

In real tenpin bowling, if you get a strike or a spare on the tenth frame, you get an eleventh frame to determine your bonus points, and if you were lucky enough to get a strike on the tenth and eleventh frames, you would get a twelfth frame.

In this game, there are no eleventh and twelfth frame, so to determine any bonus points you are entitled to after the tenth frame, look back at the words you scored in the first and second frames.

Theoretical maximum points is 300 (for 10 strikes), but anything over 100 is respectable. I’ve no idea what is the most points achievable with this selection, and will be playing along with everyone else!

 

 

 

 

 

Puzzle of the Week #62 - Tenpin Bowling

The object of this game is to try to score as highly as possible by using letters in a given rack to form words. Just like in real ten pin bowling, you have a maximum of two attempts at each rack.

If you get a ten-letter word, that is a Strike and is worth 20 points.

If you find two words that between them use each of the ten pins once each, that is a Spare and is worth 15 points.

Any fewer than that, just total up the letters used to give your point total. So if you find a five-letter word and a three-letter word, that rack will have scored you 8 points.

I have randomly generated the racks by drawing 50 scrabble tiles out, discarding only the blanks (unlike the previous outing of this puzzle, where I tweaked it so that at least a spare was achievable on each rack - this way I can legitimately take part myself).

What is the highest total you can achieve over the five racks?

Puzzle of the Week #61 - Power Play

61 raised to the power of 61

or 61 61’s all multiplied together,

or 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61 x 61

is a very large number, with 109 digits altogether.

What are the last three digits?

Puzzle of the Week #60 - Countries

1: Which country’s name, when you insert ‘GRA’ in the exact centre, becomes a common English word?

2: Which country’s name ends with the letter H?

3: Which country’s name, when you insert ‘OR’ in the exact centre, becomes a common English word?

4: Apart from Belgium, which European country’s name ends with the letter M?

5: Which country’s name is an anagram of the name of a Hollywood actress most famous in the 1990s?

Puzzle of the Week #59 - Matching Circles

I have a triangle with a strange property. I find that when I draw a line from the top corner to the base that is precisely 60cm long, the incircles I can draw in the two parts are exactly the same size. The distance between the centres is exactly 24cm.

What is the length of the base of the triangle?

Puzzle of the Week #58 - Triples: Actors

I have taken ten 9-letter surnames of famous actors and actresses, split them into three-letter chunks, and mixed them up. Your task is to reassemble them.

ARD     BLA     CAS     CHE     CLI     DEP     ELD     ETT     FAI     FFE     GER     HOL     ICH     IER     IEU     KOV     LAN     LWE     MAL     MAN     NCH     NIC     NKS     RAD     RBA     SFI     SON     TER     VAL     ZEL

Puzzle of the Week #56 - Ten Pin Bowling

The object of this game is to try to score as highly as possible by using letters in a given rack to form words. Just like in real ten pin bowling, you have a maximum of two attempts at each rack.

If you get a ten-letter word, that is a Strike and is worth 20 points.

If you find two words that between them use each of the ten pins once each, that is a Spare and is worth 15 points.

Any fewer than that, just total up the letters used to give your point total. So if you find a five-letter word and a three-letter word, that rack will have scored you 8 points.

What is the highest total you can achieve over the five racks?