How to find Per Kg Cost of my goods , Please help !!

[bhuvanesh249]

Problem : The cost of Type I Thing is Rs. 22 per kg and Type 2 is Rs 140 per kg. If both Type 1 and Type 2
are mixed in the ratio 7: 3,

I have purchased 65 Kg goods in 3200 so per kg of cost is calculate is below : 49.67

1 kg price is 3200 / 65 = 49.67


but when i calculate per kg cost according to mixture its different like : 57.4

(22*7 + 140 * 3)/10 = 154 + 420 = 57.4

so can you please someone tell me why is difference between

57.4 - 49.67 = 7..7

 

[Otis]

… If both Type 1 and Type 2 are mixed in the ratio 7: 3,
I have purchased 65 Kg goods [for Rs 3200] …

Hi bhuvanesh. 3200 is not the correct cost, for 65kg of a 7:3 mixture.

65kg would consist of 45.5kg Type 1 mixed with 19.5kg Type 2. The cost would be:

45.5(22) + 19.5(140) = 3731

3731/65 = 57.4

?

 

[bhuvanesh249]

Hi Otis thanks for the reply, here the case

I have billed of 3200 which describe that

Type 1 Goods is 22 per kg so i have purchased Type 1 : 50 kg which is 22 * 50 = 1100
Type 2 Goods is 140 per kg i have purchased Type 2 : 15 kg which is 140 * 15 = 2100

Which is 1100 + 2100 = 3200 and 15 + 50 kg = 65 kg
1 Kg price in real 3200 / 65 = 49

but when i mixed individual like i mixed



Type 1 : 300 grams : cost 140 * 0.3 = 42
Type 2 : 700 grams : cost 22 * 0.7 = 15.4

so for 1 kg mixture cost 42 + 15.4 = 57.4

I am confused that when i calculate 1 kg price with my purchased figure it cost me 49 but when i calculate with mixture ratio it cost me different, did you understand my concern ?

 

[Otis]

… i have purchased Type 1…50 kg [and] Type 2…15 kg …

Okay, bhuvanesh, but 50:15 is not the same ratio as 7:3. You're talking about two different things, so they won't be the same.

?

 

[HallsofIvy]

7+ 3= 10 so you have 7/10 is type 1 and 3/10 is type 2. If you purchased 65 kg of the mixture then you bought (7/10)(65)= 7(6.5)= 45.5 kg of type 1 and (3/10)(65)= 3(6.5)=19.5 kg of type 2. (And check that 45.5+ 19.5= 65.) So, assuming that you are not charged for the mixing, you should pay Rs. 22(45.5)+ 140(19.5)= Rs 2730

 

[bhuvanesh249]

thanks @Otis and @HallsofIvy

really appreciated, I Understand now.

 

[Otis]

… Rs. 22(45.5)+ 140(19.5)= Rs 2730

… 45.5(22) + 19.5(140) = 3731

 

[HallsofIvy]

I remember when multiplication used to be commutative!

Yes, Otis was right and I was wrong. I need to get my calculator fixed!