How many litres of milk needs to be added to 15 litres of water and mi

Question

How many litres of milk needs to be added to 15 litres of water and milk solution having 70% milk to result in a solution having 90% milk?

A. 20 litres 
B. 25 litres 
C. 30 litres 
D. 35 litres 
E. 40 litres

fauji · Answer

Approach:

- Given Proportion of Milk and Water in 15 Litre solution: 10.5L and 4.5L

- Presently, Water is 30% of solution and Milk is 70% of solution.

- In order to Make milk as 90% of Sol, water should be 10% of new solution.

So, assume new solution is x.

10% of x = 4.5 => (10/100)x = 4.5 => x = 45

- To make 90% milk solution, we need to add 30 L more(10.5+30=40.5L).

Option C!

firas92 · Answer

https://gmatclub.com/forum/weighted-ave ... l#p1586060 \frac{x}{15}=\frac{90-70}{100-90} x=15*(\frac{20}{10})=30 Answer is (C) Posted from my mobile device

Bhavika468 · Answer

originally milk=10.5, water=4.5, solution=15
now milk= 10.5+x, water=4.5, solution=15+x
acc. to ques:
10.5+x=90/100(15+x)
=>10.5+x=13.5+0.9x
=>0.1x=3
=>x=30

MathRevolution · Answer

Total: 15 liters

Milk: 70% =  \frac{70}{100} * 15 = 10.5

Water: 15 - 10.5 = 4.5

Let 'x' liters of milk is added

=>  \frac{10.5 + x }{ 15 + x} = \frac{9}{10 }

=> 105 + 10x = 135 + 9x

=> x = 30

Answer C

DHRJ0032 · Answer

70% 100%
 
 90%

10 20
 i.e the ratio of solution to milk added will be 1:2
so for 15 l of solution , 30 litres of milk needed to be added.

C it is

Crytiocanalyst · Answer

it's simple eqn that being

x/15 = 90-70/100-90
=>x=30 
therefore IMO C

CrackverbalGMAT · Answer

15 litres of water and milk solution having 70% milk and 30% water has 15 * 0.3 =4.5 lit water and 15-4.5 = 10.5 lit milk.

We need 10% water and 90% milk. This 10% will be equal to 4.5 lit.

100% of the new solution = 4.5/10 * 100 = 45 lit of solution

So the milk content in the 45 lit solution = 45-4.5 = 40.5 lit

Amount of milk added = 40.5 - 10.5 = 30 lit
 (option c)

D.S
GMAT SME

bumpbot · Answer

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How many litres of milk needs to be added to 15 litres of water and mi

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How many litres of milk needs to be added to 15 litres of water and mi

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