ratio and proportion

ziya ahmad · Joined: 16 Mar 2006 Posts: 6

hello guys,can any one solve this problem.

1)The contents of two vessel containing water and milk are in the ratio 1:2 and 2:5 are mixed in the ratio 1:4.The resulting mixture will have water and milk in the ratio------

2) Three glasses a,b and c with their capacities in the ratio 2:3:4 are filled
with a mixture of spirit and water.the ratio of spirit to water in A,B
and C is 1:5:, 3:5 and 5:7 respectively.If the contents of these glasses are mixed together,find the ratio of spirit to water in the mixture.

baskar · Site Admin Joined: 11 Apr 2004 Posts: 41

Question 1

First mixture water and milk ratio 1:2 (total 3 parts)

Second mixture water and milk ratio 2:5 (total 7 parts)

They are mixed in the ratio 1 : 4.

So, assume you take 21 litres of the first mixture and 84 litres of the second mixture. 21 is 1 part and 84 is 4 parts. 21 is arrived by finding LCM of 3 parts and 7 parts.

Now, 21 liters of first mixture will have 7 litres of water and 14 litres of milk.

84 litres of second mixture will have 24 litres of water and 60 litres of milk.

So, when you mix you will have 31 litres of water and 74 litres of milk.

CZ@@@H@@@R · Serious about CAT Joined: 14 Jan 2006 Posts: 64

Ratio of weighted average = (1/3 x 1+ 2/7 x 4) / (2/3 x 1 + 5/7 x 4) = 31/74

ziya ahmad · Joined: 16 Mar 2006 Posts: 6

dear friend u have shown such a terrific method,but i'am anxious that how did u get it,plz tell me in which question we can apply this type of technique.

CZ@@@H@@@R · Serious about CAT Joined: 14 Jan 2006 Posts: 64

(2) Ratio of weighted average = (1/6 x 2 + 3/8 x 3 + 5/12 x 4)/ (5/6 x 2 + 5/8 x 3 + 7/12 x 4) = 25/47