Question 1206959
<font color=black size=3>
Answer:  <font color=red size=4>4:15 PM</font>


Explanation


x = number of minutes after 2:30 PM
y = fraction representing how full the tank is.
y = 0 means the tank is completely empty.
y = 1 means the tank is completely full.


The water is leaking at a constant rate. Which will mean we can use a linear equation. 


We have the two points on this line which are (0,3/5) and (55, 2/7)
The 55 refers to 55 minutes after 2:30 PM to arrive at 3:25 PM.


Note: The jump from 2:30 to 3:30 is 1 hour, aka 60 minutes, so we subtract off 5 minutes to go from 2:30 to arrive at 3:25.


I'll skip a few steps but the equation of the line through those points mentioned is y = (-1/175)x + 3/5


We want to know when the tank will be empty, so we want to determine x when y = 0.


y = (-1/175)x + 3/5
0 = (-1/175)x + 3/5
(1/175)x = 3/5
x = 175*(3/5)
x = 105
It takes 105 minutes to go from 3/5 full to completely empty.


105 min = 60 min + 45 min
105 min = 1 hr + 45 min


Now add this duration to 2:30 to see where we end up.
From 2:30 to 3:30 is 1 hour.
From 3:30 to 4:00 is 30 minutes.
From 4:00 to <font color=red>4:15</font> is another 15 minutes (30+15 = 45 minutes total)


Or...
The jump from 2:30 PM to 4:30 PM is 2 hours
Rewind the clock 15 minutes to go from 4:30 PM to <font color=red>4:15 PM</font>
Rewinding those 15 minutes means the 2 hour duration is adjusted to 1 hour+45 minutes. 



Therefore, the time gap from 2:30 PM to <font color=red>4:15 PM</font> is 1 hour+45 minutes aka 105 minutes.


--------------------------------------------------------------------------


Tutor @mananth made a mistake.
The tank doesn't start off 100% full, so we don't need to drain 100% of the contents. 
Instead we need to drain 3/5 = 0.6 = 60% of the contents.


If you solved (11/35)/55 = 1/x then you'll get x = 175
While this is a correct solution to this equation, the equation itself is set up wrong. 
The "1" on the right hand side should be 3/5 to represent the fractional amount we need to drain.
The "1" on the right hand side represents 100% full. 


If you solved (11/35)/55 = (3/5)/x, then you'll get x = 105 which then leads to <font color=red>4:15 PM</font> as mentioned above.
</font>