Question

A mixture of liquids P, Q and R, contains the three in the ratio 2:4:7 respectively. P and Q are added till the ratio becomes 7:4:2. Find the ratio of the amounts of
P and Q added.​

Answer 1

Step-by-step explanation:

the correct answer is 9:4

Answer 2

Answer:

Step-by-step explanation:

Initially the ratio is 2: 4: 7

so let the quantity be 2x , 4x , 7x for p , q, r respectively

after adding p and q , the ratio is 7: 4: 2

let the quantities of the added solutions be 7y , 4y , 2y for p,q,r respectively.

Here note that p and q are the only quantities added, so r is fixed which means 7x = 2y => y = 7/2x

so ratio of p , 7y => 7* 7/2x = 49/2 x

similarly ratio of q, 4y => 4* 7/2x = 14 x

the ratio of added quantity p = 49/2 x - 2x = 22.5 x

and   ratio of added quantity q = 14 x - 4x = 10 x

so ratio of p/ q = 22.5/10 = 9/4.

answer  = 9/4