Question

in a list of an integral, 3 of the integers are even, and the rest are odd. if an integral is selec6 is 4/5 that the integer will be odd. how many integral are in the list.

Answer 1

Let there are x integers in the list.

The number of odd integers is x - 3.

The probability for odd integers is,

$\frac{x-3}{x}$

The equation for the x is,

$\frac{x-3}{x}=\frac{4}{5}$

Simplify the equation to obtain the value of x.

$\begin{gathered} \frac{x-3}{x}=\frac{4}{5} \\ 5(x-3)=4x \\ 5x-15=4x \\ 5x-4x=15 \\ x=15 \end{gathered}$

So, number of integers in the list are 15.