There are 5 red counters and y y\,y blue counters in a bag.
Imogen takes a counter from the bag at random.
She puts the counter back into the bag.
Imogen then takes another counter at random from the bag.
The probability that the first counter Imogen takes is red and the second counter Imogen takes is red is 19\displaystyle \frac{1}{9}91
Work how many blue counters are in the bag.