Answer:
To drain the water tower it will take 36 hours.
Step-by-step explanation:
Given:
A 72,000 water tower is being drained, and in an hour 2000 gallons are drained.
Now, to calculate the hours it would take to drain total 72,000 gallons of water, we should divide the gallons of water drained in one hour by total gallons of water in the tower.
Gallons of total water in the tower ÷ Gallons of water drained per hour
Therefore, to drain the water tower it will take 36 hours.
Answer:
the probability that at least one envelope is a yellow envelope is 16/21
Step-by-step explanation:
The probability that at least one envelope is a yellow envelope is P(Y);
P(Y) = 1 - P(Y)'
P(Y)' is the probability that no envelope is a yellow envelope.
Given;
red envelope = 1
blue envelopes = 3
green envelopes = 2
yellow envelopes = 3
Total = 9
Number of non-yellow envelope = 9 -3 = 6
(6 envelope are not yellow)
P(Y)' = P1 × P2 × P3
Since there is no replacement;
P(Y)' = 6/9 × 5/8 × 4/7
P(Y)' = 5/21
From equation 1;
P(Y) = 1 - 5/21
P(Y) = 16/21
the probability that at least one envelope is a yellow envelope is 16/21.
