Aptitude - Alligation or Mixture

Answer: Option A

Explanation:

Let C.P. of 1 litre milk be Re. 1

Then, S.P. of 1 litre of mixture = Re. 1, Gain = 25%.

C.P. of 1 litre mixture = Re.		100	x 1		=	4
		125				5

By the rule of alligation, we have:

C.P. of 1 litre of milk C.P. of 1 litre of water
Re. 1	Mean Price Re. 4 5	0
4 5		1 5

Ratio of milk to water =	4	:	1	= 4 : 1.
	5		5

Hence, percentage of water in the mixture =		1	x 100	%	= 20%.
		5

Answer: Option D

Explanation:

S.P. of 1 kg of mixture = Rs. 9.24, Gain 10%.

C.P. of 1 kg of mixture = Rs.		100	x 9.24		= Rs. 8.40
		110

By the rule of allilation, we have:

C.P. of 1 kg sugar of 1st kind Cost of 1 kg sugar of 2nd kind
Rs. 9	Mean Price Rs. 8.40	Rs. 7
1.40		0.60

Ratio of quantities of 1^st and 2^nd kind = 14 : 6 = 7 : 3.

Let x kg of sugar of 1^st be mixed with 27 kg of 2^nd kind.

Then, 7 : 3 = x : 27

x =		7 x 27		= 63 kg.
		3

Answer: Option D

Explanation:

Amount of milk left after 3 operations =		40		1 -	4		3	litres
					40

=		40 x	9	x	9	x	9		= 29.16 litres.
			10		10		10

Answer: Option A

Explanation:

By the rule of alligation, we have:

Strength of first jar Strength of 2nd jar
40%	Mean Strength 26%	19%
7		14

So, ratio of 1^st and 2^nd quantities = 7 : 14 = 1 : 2

Required quantity replaced =	2
	3

Answer: Option A

Explanation:

Let C.P. of 1 litre milk be Re. 1.

S.P. of 1 litre of mixture = Re.1, Gain =	50	%.
	3

C.P. of 1 litre of mixture =		100 x	3	x 1		=	6
			350				7

By the rule of alligation, we have:

C.P. of 1 litre of water C.P. of 1 litre of milk
0	Mean Price Re. 6 7	Re. 1
1 7		6 7

Ratio of water and milk =	1	:	6	= 1 : 6.
	7		7