Question

In a class of 35 ,studenta are numbered from1 to 35.the ratof boys to girls is 4:3.The roll number of students begin with boys and end with girls.find the probability that a student selected either a boy with prime roll number or a girl with composite roll number or an even roll number​

Answer 1

Step-by-step explanation:

4x+3x=35

7x=35

X=35/7=5

So number of boys is 4 ×5= 20

Number of girl 3×5 =15

So roll number of boys 1,2,3,4.....20

Roll number of girl 21,22,23.....35

So now P(boy with prime roll number) 8/20 [prime rolls/Total roll ofboys]

So now P(girl with composite roll number)12/15