Random Puzzles 

Workings

Hint
2, 3, 5, 7, 11, 13, 17, 19, 23, …

Answer
29.

The first ten prime numbers are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29.

Workings

Hint
Try working backwards.

Answer
15.

Reasoning
One quarter of 360 is 90.

One third of 90 is 30.

One half of 30 is 15.

Workings

Hint
Look at the first and third columns first.

Answer
The missing sum is 40.
Circle   = 12
Star     = 3
Square   = 7
Triangle = 9

Reasoning
Looking at Column 1 and Column 3 we have:

[1]   Square + Star + Circle + Square = 29
[2]   Square + Square + Triangle + Star = 26

If we subtract [1] – [2] we get:

[3]   Circle – Triangle = 3

And Row 3 is:

[4]   Circle + Circle + Triangle + Circle = 45

If we add [3] + [4] we get:

Circle + Circle + Circle + Circle = 48

So, Circle = 12.

Using [3] we find that Triangle = 9.

Using Column 2 we find that Star = 3.

Using Row 1 we find that Square = 7.

Double-Checking
The rows add to: 35 + 26 + 45 + 25 = 131.

The columns add to: 29 + 36 + 26 + 40 = 131.

The rows and columns must add to the same number, so this could have been used a shortcut to the missing sum.

In total, there are:
   5 Squares   = 5 x 7  = 35
   5 Circles   = 5 x 12 = 60
   3 Stars     = 3 x 3  =  9
   3 Triangles = 3 x 9  = 27

Which is also a total of 131.

So all of the totals are the same, as expected.

Workings

Hint
One of the words is antelope.

Answers
rdvrk  = aardvark rndr   = reindeer prcpn  = porcupine rhncrs = rhinoceros sqrrl  = squirrel clt    = ocelot or colt frrt   = ferret sknk   = skunk or skink dnky   = donkey ntlp   = antelope