A boy will arrive at a coffee shop randomly from 1 pm to 1.40 pm . He will stay for 20 mins and then leave .

A girl will arrive at the coffee shop randomly from 1 pm to 1.50 pm . She will stay for 10 mins and then leave .

A teacher will pass through the coffee shop randomly from 1 pm to

1.30 pm . Find

(1) The probability that the teacher will meet the boy .

(2) The probability that the teacher will meet the girl .

(3) The probability that all the 3 people will meet .