So
P[G] = 7/16
P[R] = 7/16
and P[Y] = 2/16
Five days, each independent...
So you have day 1.. where you have the above probabilities.
Day 2... to day 5.
So you observe the light five times..
5 * P[G] = number of times you would see green (2.3... roughly 2 times)
5 * P[R] = number of times you see red (2.3... roughly 2 times)
and 5 * P[Y] = number of times you see yellow (.625 roughly once)
for 2, 1, 2
You have two days where you see green, and not red or yellow
two days you see red and not the other two
and one day you see yellow.
Will try to get back on this one. :) Hopefully the beginning helps a bit.