Question

A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box , find the probability that it bears .
A number divisible by 5.

Answer 1

Total number of discs$=90$

Numbers that are divisible by $5$ are $5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90$

So,Total number of discs divisible by $5=18$

$P\left(gettinganumberdivisibleby5\right)=\frac{Totalnumberofdiscswithnumbersdivisibleby5}{totalnumberofdiscs}$

$=\frac{18}{90}=\frac{1}{5}$