There are $5$ white,$7$ red,$4$ black and $2$ blue identical balls in a box. One ball is selected at random from the box. Find the probability that the selected ball is neither white nor black.

Two dice are thrown at the same time. Determine the probability that the difference of the numbers on the two dice is $2$.

Two customers,Shyam and Ekta,are visiting a particular shop in the same week (Tuesday to Saturday). Each is equally likely to visit the shop on any day as on another day. What is the probability that both will visit the shop on
$(i)$ the same day?
$(ii)$ consecutive days?
$(iii)$ different days?

$A$ game consists of spinning an arrow which comes to rest pointing at one of the regions ($1, 2$ or $3$). Are the outcomes $1, 2$ and $3$ equally likely to occur? Give reasons.

There are $5$ white, $7$ red, $4$ black, and $2$ blue identical balls in a box. One ball is selected at random from the box. Find the probability that the ball is either black or white.

$A$ balanced die is rolled twice. Then,the probability of the sum of numbers received in these two trials being even is ...........