Eve crosses two pedestrian crossings on her way to school, each of which shows
either a green or a red light when she arrives.
On one day, the lights at both crossings showed the same colour when Eve
arrived.
What is the probability that they both showed red?
Give your answer as a fraction in its simplest form.
First crossing
45
15
Red light
Green light
Second crossing
114
날
10
12
Red light
Green light
Red light
Green light