Mathematic puzzles...

[imamartian]

for starters....

can you use three mathematical symbols (eg + - / *) in the following series:

1 2 3 4 5 6 7 8 9

keeping them in the same order and making = 100?

( the equal sign is a freebie!)

 

[imamartian]

or, you're 6ft talll, and you're stood on the beach..you see a ship appear on the horizon, how far away is it?

 

[AndrewSchofield]

or, you're 6ft talll, and you're stood on the beach..you see a ship appear on the horizon, how far away is it?

I think i've heard this before - is it something like 9miles?

 

[PrenticeBoyofDerry]

for starters....

can you use three mathematical symbols (eg + - / *) in the following series:

1 2 3 4 5 6 7 8 9

keeping them in the same order and making = 100?

( the equal sign is a freebie!)

can only use 3 symbols? ie 1 * and 2+? or + - / as many times as desired

3 miles

 

[Trazor]

1 + 2 + 34 - 5 + 67 - 8 + 9 = 100
12 + 3 - 4 + 5 + 67 + 8 + 9 = 100
123 - 4 - 5 - 6 - 7 + 8 - 9 = 100
123 + 4 - 5 + 67 - 89 = 100
123 + 45 - 67 + 8 - 9 = 100
12 - 3 - 4 + 5 - 6 + 7 + 89 = 100
12 + 3 + 4 + 5 - 6 - 7 + 89 = 100
1 + 23 - 4 + 5 + 6 + 78 - 9 = 100
1 + 23 - 4 + 56 + 7 + 8 + 9 = 100
1 + 2 + 3 - 4 + 5 + 6 + 78 + 9 = 100

Answer with 3 symbols.........123 - 45 - 67 + 89 = 100

 

[PrenticeBoyofDerry]

1 + 2 + 34 - 5 + 67 - 8 + 9 = 100
12 + 3 - 4 + 5 + 67 + 8 + 9 = 100
123 - 4 - 5 - 6 - 7 + 8 - 9 = 100
123 + 4 - 5 + 67 - 89 = 100
123 + 45 - 67 + 8 - 9 = 100
12 - 3 - 4 + 5 - 6 + 7 + 89 = 100
12 + 3 + 4 + 5 - 6 - 7 + 89 = 100
1 + 23 - 4 + 5 + 6 + 78 - 9 = 100
1 + 23 - 4 + 56 + 7 + 8 + 9 = 100
1 + 2 + 3 - 4 + 5 + 6 + 78 + 9 = 100

Answer with 3 symbols.........123 - 45 - 67 + 89 = 100

clever @rse

 

[cmother1]

For an even cleverer a*se check this out

 

[Diyisfun]

In SI units, the straight line of sight distance d in kilometers to the true horizon on earth is approximately

where h is the height above ground or sea level (in meters) of the eye of the observer. Examples:

For an observer standing on the ground with h = 1.70 metres (5 ft 7 in) (average eye-level height), the horizon is at a distance of 4.7 kilometres (2.9 mi).
For an observer standing on a hill or tower of 100 metres (330 ft) in height, the horizon is at a distance of 36 kilometres (22 mi).
For Imperial units, 13 is replaced by 1.5, h is in feet and d is in miles. Thus:

Examples:
For observers on the ground with eye-level at h = 5 ft 7 in (5.583 ft), the horizon is at a distance of 2.89 miles (4.65 km).
For observers standing on a hill or tower 100 feet (30 m) in height, the horizon is at a distance of 12.25 miles (19.71 km).

 

[PrenticeBoyofDerry]

so bearing in mind the question refereed to a six footer, my answer of 3 miles wouldn't be far off.
Depending how big the persons forehead was and the closeness of their eyes to the top of the head.

 

[imamartian]

so bearing in mind the question refereed to a six footer, my answer of 3 miles wouldn't be far off.
Depending how big the persons forehead was and the closeness of their eyes to the top of the head.

You are spot on sir (according to QI the othe night !!) Well done!

 

[imamartian]

For an even cleverer a*se check this out

Ah so it turns out you lot are 'googling' the answers eh? tut tut!

 

[imamartian]

Here's another one that entertained me for a few years during my youth...

You can use any mathematical symbol (that'll come back to haunt me!!) and the numbers 4,4,4 and 4. The objective is to make as many numbers (integers) as you can from 0 upwards, combining the 4's and the symbols!

For example (to get you started):

0 = (4/4) - (4/4)
1 = (4/4) - 4 + 4
2 = (4/4) + (4/4)
3 = ... now then....?

You can use powers (4^4) and factorial 4!
Roots are tricky, but i'm sure you'll find a way.

Lots are easy, and then they get hard..... good luck!

 

[PrenticeBoyofDerry]

For an even cleverer a*se check this out

Ah so it turns out you lot are 'googling' the answers eh? tut tut!

Cheating berstards,
I solved mine using the ship ahoy method

 

[imamartian]

anyone done the four 4's yet?

 

[imamartian]

Here's a really easy one for you...

pick three positive (above zero) integers (whole numbers) whose sum is the same as their product. Or in other words, give the same answer if you add them together or if you multiply them together....

x + y + z = x * y * z

and then do the same for 2 digits....
and then 4 digits.

(oh, and Dont google the answer !!! or at least don't post it if you do!!)