A numbered wheel is divided into eight sectors of equal size, as shown. The wheel is spun until it stops with the arrow pointing at one of the numbers.

Axel decides to spin the wheel $400$ times.

Find the number of times the arrow is not expected to point at a $4 .$

A numbered wheel is divided into eight sectors of equal size, as shown. The wheel is spun until it stops with the arrow pointing at one of the numbers.
Axel decides to spin the wheel $400$ times.

How many more times must Axel spin the wheel so that the expected number of times that the arrow points at a $4$ is at least $160$ ?

A bag contains black and white counters, and the probability of selecting a black counter is $\frac{1}{6}$.

What is the smallest possible number of white counters in the bag?

A bag contains black and white counters, and the probability of selecting a black counter is $\frac{1}{6}$.

Without replacement, three counters are taken from the bag and they are all black. What is the smallest possible number of white counters in the bag?

Find the probability that the number rolled with an ordinary fair die is:

a prime number or a $4$

Find the probability that the number rolled with an ordinary fair die is:

a square number or a multiple of $3$