ans: 3,600 litters.
Let, the capacity of the cistern be x liters
The pipe can fill in 1 minute = 4 liters
The pipe can fill in 60 minute = 4 x 60 = 240 liters
Time to fill the whole cistern = $\frac{x}{240}$hrs.
so in $\frac{x}{240}$ hrs the pipe can fill = 1 cistern
In $\frac{x}{240}$ hrs the pipe can fill = $\frac{x}{240}$ part of the cistern
Again, the leak can empty in 1 hrs. $\frac{1}{6}$ part of the cistern.
And now, in 1 hr. they can empty $\frac{1}{10}$ part of the cistern
So we can from the following equation
=> $\frac{1}{6}$ – $\frac{1}{10}$ = $\frac{240}{x}$
=> $\frac{10-6 }{10\times 6}$ = $\frac{240}{x}$
=> 4x =240 x 60
=> x = $\frac{240\times 60}{4}$
x = 3600
ans: 5.
Let, the distance of the station from my house = x km.
Here, total time = 5 + 10 = 15 minutes =$\frac{15}{60}= \frac{1}{4}$ hour
According to the question,
$\frac{x}{4}-\frac{x}{5} = \frac{1}{4}$
=> $\frac{5x-4x}{20} = \frac{1}{4}$
=> x = $\frac{20}{4}$
x = 5
ans: 90°
PS = RS
$\angle$SRQ = $\angle$SPR = 30°
$\angle$PSR = 120°
So, $\angle$QSR = 60°
Here, SQ = RS
SO, $\angle$SQR = $\angle$SRQ
As $\angle$QSR = 60°
$\angle$SQR = $\angle$SRQ = 60°
$\angle$x =180° – (60° + 30°) = 180° – 90° = 90°
