Part 1
step 1
The probability that is a truck accident is
P=6.2/(13.4+6.2+0.176)
P=0.314
step 2
The probability that is a motorcycle accident is
P=0.176/(13.4+6.2+0.176)
P=0.09
therefore
The probability that is a truck accident or a motorcycle accident is
P=0.314+0.09
P=0.404
part 2
we have that
The probability that is a truck accident is
P=6.2/(13.4+6.2+0.176)
P=0.314
therefore
the probability that not a truck accident is
P=1-0.314
P=0.686