Questions

The playground of baseball is known as Baseball Diamond or the ball field.

Number of spectral lines from a state n to ground state is

                   n(n-1)/2 = 6

From the hints,

Only two options for 1st and 2nd digits => 4,2 and 9,3 since it is single digits

Sum of second and third digit  = 10 

If 2 => 3rd digit = 8

If 3 => 3rd digit = 7

4th digit = 2nd digit + 1 => (2+1 =3) or (3+1 = 4)

Sum of all digits = 30

Let 5th digit be x

=> 1st possibility = 4 + 2 + 8 + 3 + x = 30 => x = 13 (Not possible since it has 2 digits)

=> 2nd possibility = 9 + 3 + 7 + 4 + x = 30 => x = 7

Therefore, the PIN is 93747 

F9 keystroke is used for updating a field.

In the given options, "His stomach rumbled like an approaching train" is an example of Simile.

All the other options are examples of metaphors. 

Simile and Metaphor are both figure of speeches in English which are used for comparing things but the only difference is Simile uses LIKE or AS words in comparing and metaphor directly compares without using any words.