What does the term "zero-day vulnerability" mean in

Three different positions of the same dice are shown. Find the number on the face opposite the face showing ‘5’.

Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different.

Which letter-cluster will replace the question mark (?) in the following series?

BDF, HKN, PRT, VYB, DFH, ?

Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.

_ c _ d d _ c a _ c b d d b _ a

Select the Venn diagram that best illustrates the relationship between the following classes.

Vehicle, Car, Motorbike

Six persons, Vinay, Madhav, Nilesh, Sagar, Arvind, Rajesh, are standing in two rows facing towards each other such that three persons are in a row.

Statements:

Some rats are mats.

All mats are ants.

Conclusions:

I. Some rats are ants.

II. Some ants are mats.