Step-by-step explanation:
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Answer:
Answer is

Step-by-step explanation:
Given that there are two urns. First urn contains 3 white balls and 6 yellow balls and the second urn contains 7 white balls and 3 yellow balls.
A ball is drawn from each urn.
Probability for ball from urn I is white = no of white balls/total balls in I urn

Probability for ball from urn II is white = no of white balls/total balls in I urn

Since drawing one ball from each urn is independent of the other we find
Prob that both balls are white=
Prob that ball from I urn is white *Prob that ball from II urn is white
=
Answer:
(a) 3900
(b) 4800
(c) 570000
Step-by-step explanation:
We have given
(a) 
We know the algebraic equation
So 
(b) We know the algebraic equation

(c) We know the algebraic equation

Answer:
69 weeks
Step-by-step explanation:
Let the number of weeks be x.
The first tank holds 621 gallons is leaking at a rate of 4 gallons per week. This means that after x weeks, the amount of water in the tank is:
621 - 4x
The second tank holds 828 gallons is leaking at a rate of 7 gallons per week. This means that after x weeks, the amount of water in the tank is:
828 - 7x
After a certain amount of weeks, the amount of water in both tanks is the same. That means that:
621 - 4x = 828 - 7x
=> 7x - 4x = 828 - 621
3x = 207
x = 207 / 3 = 69
This means that the amount of water in the tank will be the same after 69 weeks.