Question

medhar CCE
ARITHMETIC ABILITY
3. In a vessel there was X litres of pure milk 14 litres of pure milk was taken out
from this vessel and replaced with equal amount of water This action was again
repeated, i.e. 14 litres of the new mixture of milk and water was taken out and
replaced with equal amount of water. After the second operation the respective
ratio of milk and water in the vessel is 16-9. What is the value of X ?
4) 84
1) 112

)70
5) 98​

Answer 1

4) 84 am i right

Step-by-step explanation:

this os because u have asked the valie of x

Answer 2

The value of X is:

• In a vessel, there was X L of pure milk. 14 L of pure milk was taken out from this vessel and was replaced with 14 L of water. Again 14 L of this mixture was removed and was replaced with water.
• Final milk : water = 16 : 9

• Amount of milk after n operations = $X (1-\frac{R}{X} )^n$

                Where R = amount replaced by water = 14

                            n = 2

• Amount of milk after n operations = $\frac{16}{16 + 9} X = \frac{16}{25} X$

• Putting the values in equation, we get: $\frac{16}{25} X = X ( 1 - \frac{14}{X} )^2$

                    ⇒  $(\frac{4}5})^2 = ( 1 - \frac{14}{X} )^2$

                    ⇒   $\frac{4}{5} = 1 - \frac{14}{X}$

                    ⇒ X = 70 L

• Therefore, value of X = 70 L. Option C is the correct answer.