Question

If Matthew rolls a number cube 90 times, how many times can he expect it 2 poilto land on an odd number?

Answer 1

Solution

The total face of a cube is 6

Possible odd 1,3,5

$Probability\text{ =}\frac{Possible\text{ outcome}}{Total\text{ outcome}}$

The cube is numbered one through six, and the odd numbers are therefore 1,3,5. So the probability of rolling an odd number in any given single roll is

$\frac{3}{6}=\frac{1}{2}$

Multiplying this probability by the number of times she rolls the cube gives

$\frac{1}{2}\times90=45$

The final answer

$45$