Monday, 12 February 2018

DAY 454

TWENTY-FOUR

Credit: Jon Erickson
HACKING
The Art of Exploitation, 2nd Ed.

Use each of the numbers 1, 3, 4, and 6 once and only once with any of the four math operations to total 24. You may define the order of operations. For example, 3 x (4+6) + 1 = 31 is valid, but incorrect, since it doesn't total 24.
                                                       
[Note from JA: This problem is not nearly as simple as it might appear. You'll appreciate the solution more if you try it first - before looking at the hints or answer.]

HINTS:
1. There are no parentheses, exponents, or radicals in the answer.
2. The answer involves only two math operations.
3. The answer involves fractions.
4. The answer involves division of fractions.

Answer:

[Note from JA: I was able to figure out that the answer had to involve division of fractions. I also figured out that 6 divided by 1/4 would equal 24. But what about that pesky 3? This is where I gave up. Here is the solution:] 

      
   1 - 3/4

Friday, 3 November 2017

DAY 453

Credit: Zack Guido
OF COURSE
Presented  by Will Shortz
on NPR Weekend Edition Sunday Puzzle
October 29, 2017

The equation 65 - 43 = 21 is wrong. The answer should be 22. But can you move two numbers in the equation to make a new equation that is correct? The answer remains a straightforward subtraction problem, no symbols are changed or moved, and no parentheses are needed.

Answer:

Move the 3 and the 2 to make them exponents:

65 - 4 (cubed) = 1 (squared) 

65 - 64             = 1 



Friday, 16 June 2017

DAY 452

LA Times Crossword
June 15, 2017
Brian Thomas

The four collections of letters below follow a certain pattern and are related. Can you determine what's going on?

X I F
O ST
URY

R I X
I  S T
TH Y

TFO
YIN
NER

HOT
EY I
NEG

HINTS:
#1: The letters in each set are scrambled.
#2: The shape of each set is a clue.

Answer:

The letters in each collection, unscrambled, spelled out:

SIXTY-FOUR
THIRTY-SIX
FORTY-NINE
EIGHTY-ONE - - - 3 x 3 letters - - - perfect squares



Friday, 9 June 2017

DAY 451

True or false: any score is possible in American football.

Answer:

True: A point after touchdown is 1 point and a safety is 2 points - making every odd or even number possible. (Joseph Appel)

Wednesday, 4 January 2017

DAY 450

Six sewers take six hours to sew six shirts. How many sewers will it take to sew 100 shirts in 60 hours?

Answer:

Ten sewers
Each sewer sews one shirt in six hours. 
In sixty hours one sewer could sew ten shirts.  

Credit: Abbie Salny
The SuperSmart SuperPuzzle Book

Tuesday, 1 November 2016

DAY 449

GO FORTH AND MULTIPLY
Credit: GAMES/World of Puzzles
October, 2016
Raymond Love

Can you figure out what A must be and what B must be in the multiplication problem below to make it valid? The answer is unique.

     AB
  x    A  
   BAA

Answer:

A = 8
B = 6

    86
 x   8 
  688


Monday, 26 September 2016

DAY 448

What do you think of when you see the numbers 36-24-36?

Answer:

The sides of an Isosceles triangle, of course. 

Credit:
Victor Fleming
BY THE NUMBERS