Solution:

8! minutes

Explanation:
28 days x 24 hours x 60 minutes = 40,320 = 8! minutes.

Solution:

Blue Ball: 1
Red Ball: 8
White Ball: 5

Explanation :
185 + 185 + 185 = 555

Solution:

111111111

Explanation:
It's a maths magical square root series as :
Square root of number 121 is 11
Square root of number 12321 is 111
Square root of number 1234321 is 1111
Square root of number 123454321 is 11111
Square root of number 12345654321 is 111111
Square root of number 1234567654321 is 1111111
Square root of number 123456787654321 is 11111111
Square root of number 12345678987654321 is 111111111 (answer)

Solution:

Sam : 2
Dean : 5
Castiel : 7

Age diff
7 - 2 = '5' is prime
7 - 5 = '2' is prime
5 - 2 = '3' is prime

Solution:

Solution is done below.

(0! + 0! + 0! )! =6
(1! + 1! + 1! )! =6
2 + 2 + 2 = 6
3 * 3 - 3 = 6
4 + 4 -sqrt(4) = 6
5 + 5 / 5 = 6
6 + 6 - 6 = 6
7 - 7 / 7 =6
8 - sqrt(sqrt(8+8) = 6
(9 + 9) / sqrt(9) = 6

Solution:

1 * 1 = 1
11 * 11 = 121
111 * 111 = 12321
1111 * 1111 = 1234321


Following the pattern, you can come straight at:
111111111 * 111111111 = 11=2345678987654321

Solution:

2^986

Solution:

5050

Explanation:
You must have noticed that 50 pairs of n^2 – (n-1) ^2 exist.
n^2 – (n-1)^2 = n + (n – 1)

In such case, we may as well write 100^2 - 99^2 + 98^2 - 97^2 + 96^2 - 95^2 + ... + 2^2 - 1^2 as 100 + 99 + 98+ ... + 2 + 1 = (100 x 101)/2 = 5050

Solution:

SIX - 9 (IX) = S
9 (IX) - 10 (X) = I
40 (XL) - 50 (L) = X

=> SIX

Solution:

450

Explanation:
60 / 2(10+5) = ?
60 / 2(15) = ?
60 / 2 x 15 = ?
Using the BODMAS rule, we need to apply division first.
30 x 15 = ?
450 ..... The Answer