Solution:

89

Explanation:
(1st-column-number * 2nd-column-number) + (1st-column-number + 2nd-column-number) = 3rd column number.

i.e

(3 x 1) + (3 + 1) = 3 + 4 => 7
(6 x 4) + (6 + 4) = 24 + 10 => 34
(8 x 7) + (8 + 7) = 56 + 15 => 71
(9 x 8) + (9 + 8) = 72 + 17 => 89

Solution:

FUCK

Explanation:
IF sound like the letter 'F'
YOU sound like the letter 'U',
SEE sound like the letter 'C',
KAY sound like the letter 'K'.

It's a clever way to use word fuck and it does not get blocked by filters.

Solution:

Tug of War

Solution:

3rd.

Explanation:
Rule: Take the bottom row, flip it, and put it on the top.

Solution:

There are probably many, many solutions, five such solutions are:
> √(7^6) - 3^5
> (57 + 3)/.6
> ((3!)!- 5!)/(6 mod 7)
> floor(3*5*6.7)
> ceil(357 * sin (-6))

Solution:

569

Explanation:
Number in the triangle in ant-clockwise are: 15 12 and 18
The Central number is formed by there largest factor i.e
15=> 3 * 5 => largest factor is 5
12=> 2 * 6 => largest factor is 6
18=> 2 * 9 => largest factor is 9.

Therefore required number is 569.

Solution:

It can be done as shown below.

Solution:

24

Explanation:
21 * 4 - (4 * 4) = 68
12 * 4 - (4 * 4) = 32
17 * 4 - (4 * 4) = 52
10 * 4 - (4 * 4) = 24

Solution:

As shown in solution picture, flip the first number and stack on the second number, you will get fish eight and triangle respectively.

Solution:

This type of puzzle is referred to as an informal fallacy puzzle. The general idea is that the logic that is presented to the user appears at first glance to be correct, but in actuality has an error in it.
Actually,
Total pound spend by elder brothers = 9+9 = 18
=>17spend on shoes + 1pound (Kylian kept for himself)