Solution:

252

Explanation:
A unique pattern has been made into use in this series.
All numbers are (n^3 + n^2) where n is 1, 2, 3 and so on.

In first number, n = 1
1^3 + 1^2 = 1 + 1 = 2

In second number, n = 2
2^3 + 2^2 = 8 + 4 = 12

In third number, n = 3
3^3 + 3^2 = 27 + 9 = 36

In fourth number, n = 4
4^3 + 4^2 = 64 + 16 = 80

In fifth number, n = 5
5^3 + 5^2 = 125 + 25 = 150

Similarly for the sixth number, n = 6
6^3 + 6^2 = 216 + 36 = 252.

Solution:

74658

* 8 + 6 =14
* 5 - 4 = 1
* 7 = 2*4 - 1
* 4 + 6 = 10
* 7+4+6+5+8 = 30

Solution:

'five'

Its the count of alphabet

Solution:

This can be done if you draw a five pointed star and place the balls on the corners and intersection points. See the figure to understand better.

Solution:

Solution is below

Solution:

The man asked the king that he wanted to die of old age.

Solution:

The bridge won't break.

When the car has travelled half of the bridge, that is 15km, the car must have used more than 300 grams of fuel. Therefore, the impact of bird's added weight will be zero literally.

Solution:

10

Explanation:
Equation 1 + 9 + 11 = 1 can be derived from
One (o) + nine (n) + eleven (e) = one => 1

Similarly for equation,
12 + 11 + 9
Twelve (t) + eleven (e) + nine (n) => ten (10)

Solution:

2 degree below zero

Solution:

60 minutes

Explanation:
Roy will be able to consume all the five tablets in an hour.

Tablet 1 will be taken in 0 min.
Tablet 2 will be taken in 15 min.
Tablet 3 will be taken in 30 min.
Tablet 4 will be taken in 45 min.
Tablet 5 will be taken in 60 min.

Solution:

NONE, holes are empty.