Answer:
1. The probability that the T-shirt will be grey :-
=》

=》

=》

hence, the probability of grey t-shirt is 0.1
2. The probability that the T-shirt will not be red :-
=》

=》

=》

=》

The probability that the T-shirt will not be red is
0.8
3. He takes one of his blue T-shirts at random.
What is the probability that the T-shirt is light blue
total blue t-shirts = 5
so, the probability of choosing light blue t-shirt is
=》

=》

=》

hence, the probability of choosing light blue t-shirt is 0.2