Answer:
11 am
Step-by-step explanation:
Bus A and Bus B leave the bus depot at 9 am.
Bus A takes 30 minutes to complete its route once
Bus B takes 40 minutes to complete its route once.
We solve this finding the Lowest Common Multiple of the minutes each bus uses to complete it's route
30 = 3 × 10
40 = 4 × 10
= 3 × 4 × 10
= 120 minutes
120 minutes after 9 am is
60 minutes = 1 hour
60 minutes = 1 hour
= 2 hours.
9am + 2 hours
= 11 am.
Therefore, they be back at the bus depot together at 11 am
The probability that none of the four have been vaccinated is
(1-0.63)^4 = 0.01874161
The probability that at least one has been vaccinated is the complement of this,
≈0.9813
I’m Not good at This but I’ll try to help ;c
Ye answer to that would be b
