farukqmul wrote:

Two alloys A and B are composed of two basic elements. The ratios of the compositions of the two basic elements in the two alloys are 5 : 3 and 1 : 2, respectively. A new alloy X is formed by mixing the two alloys A and B in the ratio 4 : 3. What is the ratio of the composition of the two basic elements in alloy X ?

(A) 1 : 1

(B) 2 : 3

(C) 5 : 2

(D) 4 : 3

(E) 7 : 9

**Edit: **Source -> NOVA.

Element 1's proportion to the total of each liquid:

A -> 5/8

B -> 1/3

You want alloy X to be formed with 4/7 of it coming from liquid A and 3/7 coming from liquid B, hence:

5/8 * 4/7 + 2/3 * 3/7 = x (...) -> x = 7/14 which is 1/2. For element 1.

The proportion of element 2 coming from each liquids will be the same, and obviously the ratio will also be 1/2. Thus, answer A is the right one.