Directions:
A health-drink company's in R & D department is trying to make various diet formulation, which can be used for certain specific purpose. It is considering a choice of 5 alternative ingredients (O, P, Q, R and S), which can be used in different proportions in the formulations. The table below gives the composition of these ingredients. the cost per unit of each of these ingredients is as O: 150, P: 50, Q: 200, R: 500, S: 100.

Question:
In what proportion P, Q and S should be mixed to make a diet having least 60% carbohydrate at the lowest per unit cost?

Option A):
4:1:2
Option B):
2:1:3
Option C):
2:1:4
Option D):
3:1:2
Option E):
4:1:1

Correct Answer is Option E):
4:1:1

Explanation:
To make diet with at lest 60% carbohydrate we can use option (2) and (5) only, but the lowest cost per unit can be given by when P, Q and S are mixed in the ratio 4:1:1.