Question

8 litres are drawn from a flask containing milk and then filled with water. The operation is performed 3 more times. The ratio of the quantity of milk left and total solution is 81/625. How much milk the flask initially holds?

Answer 1

Step-by-step explanation:

Let initial quantity be Q, and final quantity be F

F = Q(1 - 8/Q)4^4

=> Q = 20

Answer 2

Answer:

20 litres

Step-by-step explanation:

Let the initial quantity of milk be x .

When a container contains "x" unit of liquid from which " z" unit of of liquid  are taken out for n of of times then,

Quantity of pure liquid  $= x ( 1 - \frac{z}{x} )^{n}$

The ratio of quantity  milk left and total solution

  $= \frac{81}{625} = (\frac{ x ( 1 - \frac{z}{x} )^{n}}{x} )$

⇒  $\frac{81}{625} = ( 1 - \frac{8}{x} )^{4}$

⇒ $( \frac{3}{5} )^{4} = ( 1 - \frac{8}{x} )^{4}$

⇒ $( 1 - \frac{8}{x} ) = \frac{3}{5}$

⇒ x = 20 litres