Random Puzzles 

Workings

Hint
How can the answer end in 9?

Answer
4,217 x 5,237 = 22,084,429.

Reasoning
The only way the answer can end in 9 is if the two numbers both end in 7 (7 x 7 = 49).

The only way we can reach 22 million is if the two numbers begin with 4 and 5 respectively.

This leaves each number with just 2 options, and the answer is quickly found.

Workings

Hint
Think of the pages from 1-9, and then 10-99.

Answer
There are 147 pages. The number 3 appears 35 times.
Answer #1
For pages 1-9, there are 9 pages, which is 9 digits.

For pages 10-99, there are 90 pages, which is 180 digits.

This is a total so far of 189, therefore we require another 333-189 = 144 digits, which is another 144 ÷ 3 = 48 pages.

Taking us to 9 + 90 + 48 = 147 pages in total.

Answer #2
From page 1 to 147 we have 15 pages that end in 3:

   3, 13, 23, ..., 143

We also have the ten pages that start with 30:

   30, 31, 32, ..., 39

Plus the ten pages that start with 130:

   130, 131, 132, ..., 139

For a total of 15 + 10 + 10 = 35 number 3's.

Workings

Hint
The country has four letters.

Answer
Peru.

The local habitat around a railway track can be very interesting. For example, supporting the track is a sleeper, under which you can find the lesser-spotted great weevil.

Workings

Hint
What is the difference between each number?

Answer
14.

Add 3 to the previous term.