Aptitude - Alligation or Mixture - Discussion

Discussion Forum : Alligation or Mixture - General Questions (Q.No. 5)
5.
In what ratio must a grocer mix two varieties of pulses costing Rs. 15 and Rs. 20 per kg respectively so as to get a mixture worth Rs. 16.50 kg?
3 : 7
5 : 7
7 : 3
7 : 5
Answer: Option
Explanation:

By the rule of alligation:

Cost of 1 kg pulses of 1st kind Cost of 1 kg pulses of 2nd kind
Rs. 15 Mean Price
Rs. 16.50
Rs. 20
3.50 1.50

Required rate = 3.50 : 1.50 = 7 : 3.

Discussion:
43 comments Page 3 of 5.

Shree said:   8 years ago
Clear and detailed explanation. Thank you.

Dinaz Khan said:   1 decade ago
I don't understand the answer please explain clearly.

Sylvester OgboluOtutu said:   1 month ago
Use x and y to represent the two variables of Rs. 15 and Rs. 20.

15x + 20y = 16.50(x + y),
15x + 20y = 16.50x + 16.50y,
20y - 16.50y = 16.50x - 15x,
3.5y = 1.5x.
35y = 15x.
7y = 3x (Divide both sides by 5).

Divide both sides by 3y.
x/y = 7/3.
x : y = 7 : 3 (Answer)

Checking:

Rs. 15 × 7 = Rs. 105
Rs. 20 × 3 = Rs. 60
Rs. 105 + Rs. 60 = Rs. 165.00
Rs. 165 ÷ 10 = Rs. 16.50 (Checked).

Vinod said:   1 decade ago
Let x=15,y=20.
We know that x+y=16.50.

We can write in eqtion form:

15x+20y = 16.50(x+y)
16.50x-15x = 20y-16.50y
1.50x =3.50y
x/y = 3.50/1.50

Just we can convert

From eq x = 350/100=35
Eqtion y = 150/100=15

There fore ratio is
x:y =35:15.

Then answer is 7:3.

Manasa said:   1 decade ago
@ladli
(20-16.50):(16.50-15)=3.50:1.50=7:3

Sheetal said:   1 decade ago
If cost of 1kg pulses of 2'nd kind is=15

& 1'st kind is=20...
then what will be the ans?

Please tell me...

It's depends upon the mean price?

Viswajit said:   1 decade ago
Thank you manasa.

San said:   1 decade ago
If we swap 15 and 20 places.

Why can't it be 3:7 ? is there any rule?

Sathish said:   1 decade ago
How we get 3.50:1.50=7:3?

Shashank said:   1 decade ago
350/100:150/100=35:15=7:3


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