Aptitude - Alligation or Mixture - Discussion

Discussion Forum : Alligation or Mixture - General Questions (Q.No. 7)
7.
How many kilogram of sugar costing Rs. 9 per kg must be mixed with 27 kg of sugar costing Rs. 7 per kg so that there may be a gain of 10% by selling the mixture at Rs. 9.24 per kg?
36 kg
42 kg
54 kg
63 kg
Answer: Option
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 1st and 2nd kind = 14 : 6 = 7 : 3.

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

Then, 7 : 3 = x : 27

x = 7 x 27 = 63 kg.
3

Discussion:
40 comments Page 1 of 4.

Avinash Rai said:   5 months ago
@All. Here's my explanation.
Let x kg of 9 Rs. sugar.
Total cost before gain = (9*x + 27*7),
and after gain = (9*x + 27*7) * 1.1 where (10% gain).

This total cost should be equal to 9.24 * (27+x)
By solving, 9.24 * (27+x) = (9*x + 27*7) * 1.1
x = 63.
(3)

Sushant said:   2 years ago
9.24 is sp with 10% profit.
Calculate cp with profit per cent formula;
Then, we get 8.4 cp.
(1)

Mangesh said:   4 years ago
Why use the 100/110? Explain, please.
(9)

Namratha said:   4 years ago
Can somebody please explain how 110/100 came, why should we take it like that and what's that?
(3)

Anushka said:   4 years ago
S.P = 9.24
CP = 9.24 * 100/110 = 8.4.

Let the qty of sugar be x;
9x + (27 * 7)/27 + x = 8.4
x= 63kg => answer.
(6)

Simran Mehta said:   5 years ago
@Jeyari.

By reducing it.
14:6- dividing both by 2 which gives 7:3.
(1)

Jeyari said:   5 years ago
Could you please explain how ratio reduced to 7:3?

Andy said:   5 years ago
First get the mean or the cost price 9.24*110/110 = 8.4.
Then (27*7)+(9*x)/27+x = 8.4(average formula).
Solving x we get 63.

Andy said:   5 years ago
The first step find the cost price 9.24 * 100/110 = 8.4.
Then equation: (7*27)+(9*X) = 8.4.
Solving X = 63.
(1)

Abhinav said:   6 years ago
According to rule of alligation cheaper should be on the left and the expensive one of the right but why 9 is on the left when it is expensive? Please tell me.
(3)


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