DAY 480

GAMES Magazine

October, 1984

Ken Fischer

 

What is the arithmetic average of the first one million odd numbers?

 

 Answer:

 

1,000,000 - The average of the first n odd numbers is always n, the number of odd numbers.

 

For example, 1 + 3 + 5 = 15 (average 3)

                        1 + 3 + 5 + 7 = 16 (average 4) 

DAY 479

If .......

9 + 3 = 15

9 + 7 = 47

8 + 5 = ? 

HINT:

The + sign may or may not mean plus.

Answer:

 

8 + 5 = 27

 

Explanation:

Multiply the two given numbers, then subtract their sum:

 

9 X 3 = 27

27 - 12 = 15, etc.

 DAY 478

There are only 10 kinds of people: those who understand binary numbers, and those who don't.

 DAY 477

Musical Limerick

Jon Saxton

In Colossal Book of Word Play

Martin Gardner

 

A dozen, a gross, and a score,

Plus three times the square root of four,

Divided by seven,

Plus five times eleven,

Is nine squared and not a bit more.*

 

*This limerick can be written out numerically as a correct equation, beginning with 12 + 144 + 20 and ending with 9 (squared) + 0.

 

 

DAY 476

 

From Brainteasers and Mind Benders 

Ben Hamilton

Use all the digits 0 - 9 to make two sums and one product.

HINT:
The product uses four digits.

Answer:

 

7 + 1 = 8

9 - 6 = 3

4 x 5 = 20

 DAY 475

A man went into a bank with exactly $1,000, all in one-dollar bills. He gave the money to a cashier and said, "Put this money into ten bags in such a way that if I call and ask for a certain number of dollars, you can hand me over one or more bags, giving me the exact amount called for, without having to open any of the bags."

How was the cashier to do this?

Answer:

 

The contents of the bags should be $1, $2, $4, $8, $16, $32, $64, $128, $256, and $489. Notice how the contents of the first nine bags are in geometric progression.

 DAY 474

REALLY SIMPLIFIED FRACTIONS

 

The numerators and denominators of these fractions use the digits 1-9 once each, without repetition.

 6729  =  1

13458     2

5832  =  1

17496    3

 4392  =  1 

17568     4

 2769  =  1

13845     5

 2943  =  1

17658     6 

 2394  =  1

16758     7

 3187  =  1

25496     8

 6381  =  1

57429     9