Alligation or Mixture Questions

FACTS  AND  FORMULAE  FOR  ALLIGATION  OR  MIXTURE  QUESTIONS

I. Alligation : It is the rule that enables us to find the ratio in which two or more ingredients at the given price must be mixed to produce a mixture of a desired price.

II. Mean Price : The cost price of a unit quantity of the mixture is called the mean price.

III. Rule of Alligation : Suppose Rs.x per unit be the price of first ingradient mixed with another ingradient (cheaper) of price Rs.y per unit to form a mixture whose mean price is Rs. z per unit, then

Quantity of cheaper : Quantity of dearer

= ( C.P of dearer - Mean Price ) : ( Mean Price - C. P of cheaper )

= ( x- z ) : ( z - y )

IV. Suppose a container contains x units of liquid from which y units are taken out and replaced by water. After  operations , the quantity of pure liquid = $x{\left(1-\frac{y}{x}\right)}^{n}$ units.

Q:

Vipin adds 3 litres of liquid A in 6 litres of liquid B and Mohit adds 8 litres of liquid A in 15 litres of liquid B. What is the ratio of the percentage of liquid B in the two mixtures?

 A) 26 : 25 B) 51 : 32 C) 46 : 45 D) 34 : 25

Explanation:

4 379
Q:

In what ratio must a mixture of 15% spirit strength be mixed with that of 25% spirit strength to get a mixture of 21% spirit strength?

 A) 1 : 3 B) 2 : 3 C) 3 : 4 D) 4 : 5

Explanation:

2 355
Q:

A mixture of 240 litres of juice and water contains 15% water. How much more water (in litres) should be added to this so that the strength of water will become 25% in the new mixture?

 A) 28 B)  32 C)  26 D)  34

Explanation:

2 345
Q:

In a mixture of 35 litres, the ratio of water and acid is 6 : 1. If 5 litres of acid is added to the mixture, then what will be the ratio of water and acid in the new  mixture?

 A) 5 : 2 B)  4 : 1 C) 3 : 1 D) 6 : 5

Explanation:

2 298
Q:

In what ratio salt costing Rs 13/kg mixed with another salt costing Rs 7/ kg to get a mixture costing Rs 9/kg?

 A) 4 : 7 B) 3 : 5 C) 2 : 3 D) 1 : 2

Explanation:

2 267
Q:

The ratio of sand to gravel in a mixture is 17 : 9 while that between gravel and cement is 6 : 17. What is the ratio of sand to cement in the mixture?

 A) 289 : 54 B) 9 : 6 C) 17 : 17 D) 2 : 3

Explanation:

1 263
Q:

25 litres of a mixture contains 30% of spirit and rest water. If 5 litres of water be mixed in it, the percentage of spirit in the new mixture is

 A) 45% B) 33 1/3% C) 25 % D) 12 1/2%

Explanation:

0 212
Q:

In a mixture of 165 litres, the ratio of liquids X and Y is 6 : 5. If 5 litres of liquid Y is added in the mixture, then what is the ratio of X and Y in the new mixture?

 A) 10 : 9 B) 8 : 7 C) 9 : 8 D) 5 : 4