I have wood but no bark,
And leaves that don’t fall,
I am made up of branches,
and come in sizes of all.
I am completely devoured many times,
over and over by a worm of a kind.
If you want to know the answer of mine,
look for the secret that I’ve stored inside.
The problem works out to a set of three equations:
b + c + d = 22
a + c + e = 22
a + b + c + d + e = 30
Solving for c = 14, leaving d = 8 – b and e = 8 – a. In other words, c must be 14, but the other two numbers just have to add up to 8. The requirement that they be unique rules out 4 + 4, so you’re left to choose from the following combations for b + d and a + e:
0 + 8
1 + 7
2 + 6
3 + 5
You are given eight coins and told that one of them is counterfeit. The counterfeit one is slightly heavier than the other seven. Otherwise, the coins look identical. Using a simple balance scale, how can you determine which coin is counterfeit using the scale only twice?
First weigh three coins against three others. If the weights are equal, weigh the remaining two against each other. The heavier one is the counterfeit. If one of the groups of three is heavier, weigh two of those coins against each other. If one is heavier, it’s the counterfeit. If they’re equal weight, the third coin is the counterfeit.
1. Canada – 202,080 km / 125,567 mi
2. Indonesia – 54,716 km / 33,998 mi
3. Russia – 37,653 km / 23,396 mi
4. Philippines – 36,289 km / 22548 mi
5. Japan – 29,751 km / 18,486 mi
6. Australia – 25,760 km / 16,006 mi
7. Norway – 25,148 km / 15,626 mi
8. United States – 19,924 km / 12,380 mi
9. New Zealand – 15,134 km / 9403 mi
10. China – 14,500 km / 9009 mi
Note: Greenland has 44,087 km of coastline but it is not yet a fully independent country.
In the marble walls as white as milk,
Lined with skin as soft as silk,
Within a fountain crystal clear,
A golden apple does appear.
No doors are there to this stronghold
Yet thieves break in and steal the gold.