Question is down below

a ) ,

b )

Step-by-step explanation:

This is a nice and short question we have here.

Given that a bag has n counters, and that one counter is blue, respectively the rest is red, if two counters are taken at random there isn't a definite percentage that one of the counters chosen is red or blue, but there is a fractional representation of this.

We could express n ( number of counters ) to form a probability of 2 / n. As you can see, two counters are taken at random over n counters, and thus we derived this fraction.

a )

____

Now we have this second part -

Therefore, there are 15 red counters. Hope that helps!

a=r

d=q

c=p

b=s

hope this !