Two liquids A and B are in the ratio 5 : 1 in container 1 and in the ratio 1 :…
20192024
Two liquids A and B are in the ratio 5 : 1 in container 1 and in the ratio 1 : 3 in container 2. In what ratio should the contents of the two containers be mixed so as to obtain a mixture of A and B in the ratio 1 : 1?
Answer: D. 3 : 4 — Find the fraction of A in each container, then apply alligation. Container 1: A : B = 5 : 1, so fraction of A = 5/6. Container 2: A : B = 1 : 3, so fraction…
- A.
1 : 2
- B.
4 : 3
- C.
3 : 2
- D.
3 : 4
Attempted by 7 students.
Show answer & explanation
Correct answer: D
Find the fraction of A in each container, then apply alligation.
Container 1: A : B = 5 : 1, so fraction of A = 5/6.
Container 2: A : B = 1 : 3, so fraction of A = 1/4.
Required mixture: A : B = 1 : 1, so fraction of A = 1/2.
By the rule of alligation, container 1 : container 2 = (1/2 - 1/4) : (5/6 - 1/2) = (1/4) : (1/3) = 3 : 4.
Check: take 3 parts of container 1 and 4 parts of container 2. A = 3 x 5/6 + 4 x 1/4 = 5/2 + 1 = 7/2; B = 3 x 1/6 + 4 x 3/4 = 1/2 + 3 = 7/2. So A : B = 7/2 : 7/2 = 1 : 1, as required. The two containers must be mixed in the ratio 3 : 4.